Do some games not get announced ahead of time?

I don't know about you guys, but I like to stay up to date on upcoming games, even if I'm not going to necessarily play them or buy them. I just am interested in knowing whats new, so I use wikipedia's "2020 in video gaming" page, for example. Ive noticed, though, that some games that didn't appear on this list just come out, and then show up on wikipedia's page afterwards. Is this because some games don't get announced? If anyone has a good answer to this, that would be appreciated, might be a dumb question.

Apex Legends and Tetris 99 are good examples from 2019 that just drop and playable at once.

Announcing way ahead of time is for two factors, to please investors, and to sell merchandise pre-release. It's all a funding strategy because some of these games are only half-way funded when announced.

Capcom have been on a role dropping games and releasing them eight/eleven months later. *Capcom seem to have a competent sales-to-marketing strategy these past few years; that really shows Capcom has freed itself from baggage/ dead weight that plagued the company and its studios priorities for quite a few years (Inafune Keiji san). Hopefully they can try and salvage the fighting game departments as well. Launch issues such as Street Fighter V and Infinite seem to cost the company more than it benefits.

I think Capcom would benefit shadow dropping a multiplatform online stress-test for a new fighting game. And make its release in the near future. Maybe even running in the RE Engine. With these times, that would be difficult to expect but here is hoping.