I think that the 20th anniversary would be the right time to announce TS5, for release in early-mid-late 2022. I also think they might get fan input along steps, so, for example, they might when they announce it release art concepts or a picture of a sim, then get our thoughts on it so they can change the art style slightly if necessary. They might then release more images, and do polls and stuff for content, etc. to get us involved while we wait, then they will probably finish the sims 4 off with a few packs in the final year. They will probably release an early trailer or video in late 2020 or early 2021 and then release more trailers every month or 2. If people aren't liking some elements and they can tweak it they probably will.
