They announced Sims 5 was in development like last year haha.
This isn't anything new tbh, when The Sims 1: Makin' Magic came out, Sims 2 was a few months from being released; when The Sims 2: Freetime came out, Sims 3 was a year from being released.
This is just sort of the normal cycle for Sims games. If you want something to actually complain about, I'm fucking pissed all of this wasn't included in City Living, or at least they waited for a giant DLC pack for City Living and building apartments/multi-family units. That's more egregious than Sims 5 not coming out quite yet.