The only things I can come up with so far are birthdays, holidays, vacations, etc. Nothing actually specific to 2025.
I guess I’m looking forward to eventually buying a new laptop, but that’s not really year specific either.
So I guess my answer is it ending. Same for the next 3 after it.
If you are assuming we live in a simulation, then you have to assume everything else about it too - there is no evidence to point in any direction about anything higher than our own layer, so ours is the only one we can do science on. All else would be imagination, so make up whatever you like.
I do agree though that a simulator can’t fully simulate itself, so yeah, it would have to be bigger and more complex in at least some way, which could simply be runtime.