I think it will be non-binary pronouns because that seems popular on twitter (or at least that's what I am getting recommended from twitter...)
I would rather have better playtesting and bug fixing. It sounds like they will actually make an attempt to improve or fix simulation lag once and for all so they should go all in to fix that.
Other than that, cars I guess, or that they will bring out a statement that the sims5 will have single player and will be a game that the fans want. Even if that game is a couple of years away, you could still announce what you intend to do with it.