Yeah I made that suggestion based on the idea that he could be trying to be a bit tricksy, and claim it was a GOTY contender when it originally released in 1999.
If he's explicitly said that it was a game from last year though then yeah Hi-Fi Rush is the most likely candidate.
Well I might have some things confused on that one; apparently they actually said it was a GOTY contender in the year it released, so it could be something earlier than last year.
However I don't see it being anything pre-360, that's for sure. I did see someone say maybe a Gears Classic Collection and that could in theory happen, but if the idea is that MS would be using it to bring attention to a new release that's Xbox console-exclusive (I see NO reason they'd do this which I'll explain in a minute), well there's no new Gears set for 2024 from what we know, or likely 2025 for that matter.
As much of a clown they are, Vigilante Joker was trying to pass the idea that maybe it could be a PS & Switch port of Killer Instinct, as a way to get attention for Killer Instinct 2 on Xbox & PC. But there's one glaring flaw in his logic: no one's going to buy an Xbox just to play a new Killer Instinct, and if that's the case there's basically no difference between releasing it on Xbox/PC or Xbox/PC/PlayStation. Since for MS, the Day 1 PC ports are mainly because they don't see those people buying Xboxes (well, that's the reality they've created for themselves now, after years of doing it at least).
My own guesses would be among: HiFi Rush, Forza Horizon 5, Pentiment, or Flight Simulator. If the last one, probably would be the new one alongside the older 2021 content. But my gut's saying it's either HiFi Rush or Forza Horizon 5, and either of them for both PS5 and Switch 2.