I don't think there will be an announcement in 2021.
Too many polls and surveys and expectations still from the fans of Sims 4. And yes we are here, we play and we spend.. and some of us have been simmers since the first game even! I know right? Amazeballs! Although really as an older simmer I am well aware my money doesn't spend any better than a younger simmers does and frankly I'm not more deserving than a new simmer because I've been here longer.
With the live service and patching and all the still possible pack themes to come out... just no, sorry. There is too many possibles to be added. That's not me just being hopeful either although personally I'd love it to continue til 2025. I'm just really certain it will be still going strong with packs coming out in 2021... and I really think beyond that even possibly till 2023.
People still want so many themes brought to this game .. new and old concepts even. Just look at the forums and twitter. Lots of expectations and wishes out there. We still don't have a number of things that can be added into this game. It still runs super smooth and can handle it too.
Keep your seatbelts buckled ... more of the same threads and arguments since 2014. Heck, if I would have believed people then I'd have thought the game was going to crash and burn the next year out of sheer embarrassment for actually being. Now... 6 years later still going strong huh?
Guess we wait and see.