I ate The Sims 5. It was delicious. Still picking the online features out of my teeth though.
As others have said, I believe the Sims 4 will likely be around for a while yet.
June 2018,
Variety Magazine sits down with SimGuruGrant.
Though EA hasn’t announced any further expansion for the four-year-old game, it appears as if “The Sims 4” will continue to have a long tale. Though he wouldn’t go into specifics, Rodiek said he was already in meetings discussing the next three years of content for the current title.
April 2019,
SimGuruDuke moves to the Senior Producer position for The Sims 4, SimGuruGrant moves to "other important and awesome things".
March 2019,
32-bit support is dropped for The Sims 4.
July 2019, Maxis revealed Sims 4
rebranding.
January 2020, The Sims Team released a large survey about the Sims 4, topics include
improving existing expansion packs.
April 2020, The Sims Team released a large
community survey for upcoming Sims 4 features.
SimGuruDuke also lays out a six-month road map for The Sims 4, including Eco Lifestyle, Nifty Knitting and an as of yet unnamed Game Pack. June 2020 -- there is speculation floating around, as has been mentioned by others, of a Sims 5 announcement at EA Play. Even in those rumours, The Sims 5 is speculated to be released over 12 months from now.
If I had to guess, based on the above information, The Sims 4 will be with us for
at least another year or two - potentially much longer. The Sims Team seems enthusiastic for making positive changes to the current iteration of the game before it's done.
It's also not up to us whether or not The Sims 5 is in development or not. It's fun to be excited about things, but I'd temper that enthusiasm for now.