Midnight had elected to make a calculated gamble, on the basis of demonstrating a clear and practical head while everyone else was in a state of panic.
Now, that did come with the complication of being potentially remembered as that one guy who just surrendered immediately when Nightmare Moon arrived... but he was hoping that it would in retrospect, once Princess Luna had resumed her normal functions, come off more as being calm and open-minded in the face of danger. A typical hostage negotiator mindset, or a police officer talking down an armed and agitated gangster.
Setting the stage for later. Midnight had to demonstrate at least one time that negotiation with an enemy could work out well if he wanted to introduce the potential for compromise later...
... though there was probably some potential for ponies to get the wrong idea on that front by using Luna's return for that. The end results weren't exactly a compromise if the other party gave up completely on their stated intentions in the end and just quietly integrated into a position in Pony society. It wasn't like that wasn't a good result, but... speaking frankly, Midnight had no presumptions that Chrysalis, for example, would be willing to shrug and just quietly assimilate after a conversation. Things would take much more effort, there.
Still, Rome wasn't built in a day.
And so when Nightmare Moon made her sudden appearance, Midnight stood his ground. Impressed, but not awed into immediate compliance or spooked into an instinctive flight response in the face of danger, as the herd behavior was swelling towards.
He had to keep his composure in order to properly play the role of Devil's Advocate. Even if people didn't agree with what he was saying, this would make sure that they remembered him saying it. That was the first step towards belief. It was almost impossible to have an entire population truly and genuinely back someone as a leader, a legendary one hundred percent approval rating, but it was often fine to just have 'enough' backing, when there were enough people who agreed with what you were saying to push you forward for leadership. But first, people had to decide it was worth listening to what you had to say. Midnight could only assume it worked the same with ponies.
So...
"-... what is the plan for handling the imminent starvation crisis among your loyal subjects? What with there being no sun, after all, and thus soon no crops that need the sun to grow." Midnight asked.
Nightmare Moon did not seem to have an immediate response for that after a couple long moments. But neither was she immediately smiting him for his presumption, so it seemed safe for Midnight to press on.
"Mushrooms and some mosses and lichens will grow even in completely sunless caves, and too much sun will actually harm them." he led in. "Cooked properly they can be quite tasty as well... well, the mushrooms at least. Though not everypony is fond of the same flavors."
"Oh! Oh yes, that's true. That would work." Nightmare Moon said, verbally stumbling for a moment before seeming to get her hooves under herself again.
"Of course, that brings up the question of logistics." Midnight pointed out. "Given that nobody is currently farming mushrooms or lichens as a wide-scale food crop so far as I'm aware, there would need to be an integration and transition period of harvesting what crops are currently in season while substitute crops are found and recipes to make use of them are developed."
Nightmare Moon hesitantly nodded, at least willing to acknowledge the point. It was encouraging enough for Midnight to press further.
"Practically speaking, it may be best to push for rapid testing of new food crops in repurposed cellar farms on volunteer groups to be sure that the results are both satisfying and nutritionally complete while preparations are underway for a larger scale reconstruction of farming efforts to better match our new, eternally nocturnal environment. That should take no longer than a year or two of rapid restructuring-"
Midnight cut himself off as Nightmare Moon suddenly loomed before him, wings flared out in agitation.
"Or not." he muttered quietly.
"We will brook no hesitation or delays in our design. Having waited one thousand years, We shall wait no longer." Nightmare Moon declared, voice dangerous.
"Of course, of course. No delays for testing or restructuring, directly into sweeping and permanent reform. Well, we'll have to take it from another angle, then." Midnight suggested. "If the world is going to be shrouded in the dark of night forever and there is no time to test for replacements... Well, with there being no sun here, it simply stands to reason that we must relocate food production to where the sun is. How plausible would you say it would be to move our farms to the moon?"
"... What?" Nightmare Moon said, wings hesitantly lowering in confusion.
"Well, it's been a thousand years, but you lived there fine." Midnight pointed out. "So the moon must be habitable to some degree, or at least in a position where it can be made habitable with some effort on your part. Perhaps a compromise could be reached where, if wholesale relocation of farms and farmers to the moon unfortunately proves to be infeasible, select regions of Equestria remain subject to a day-night cycle for the purpose of food production. With, of course, strict regulation as it comes to transit... not that your loyal subjects would attempt to avoid the moonlight and linger in the light of the sun without reason, of course..."
"Unfortunately...?" Nightmare Moon said, clearly trying to catch up to Midnight's rapid verbal prompting. "You would want to live on the moon?"
"If the moon is a terrible place to be, then it's because you cannot come and go from it as you please." Midnight pointed out. "With that in mind, any prison would be as terrible... a desert where the sun never sets, underground caverns, the ocean depths. If it were a matter of living there, and not a prison, then I wouldn't mind living on the moon, no."
Nightmare Moon's wings had settled down into a placidly comfortable and relaxed position by this point, so Midnight was hopeful. But...
"No." she declared simply. "We are most amused and not displeased by your efforts, talkative stallion. But We shall not be delayed on this matter, and we shall not be making exceptions or relocating stretches of land. If need be, We shall simply alter the nature of the moon's light such that it is suitable for growing plants."
"... Ah." Midnight said dumbly. "That is... within your power, I see."
"With that in mind, We appreciate that you have raised a relative point of concern, such that it can be suitably addressed without screaming or defiance." Nightmare Moon declared. "We shall henceforth be employing you as Our adviser for the foreseeable future."
"Oh, well, I greatly appreciate the-" Midnight began.
"This is neither a suggestion, nor a request to which you have the right to refuse." Nightmare Moon cut him off, horn glowing.
Midnight had a moment to wonder just where he had made a mistake as he was enveloped in magic and lifted off the ground in what felt like a tight grip intended to ensure he could not just fly away.
And then the Princess kidnapped him, in front of everypony.