It’s actually always been this way even since game dev teams grew beyond a handful of people. The size of the needed team starts small as the project starts, then ramps up as it continues, and then right after release you have a ton of people with suddenly (unless you’ve done very careful and difficult planning) nothing for most of them to do. And so, the standard answer is to fire the majority of them.

I have no idea what mixture is going on now of standard game industry behavior vs. now-standard tech layoffs vs. something new going on with games-industry layoffs specifically. But the trope of the game shipping, and then everyone instantly getting fired, has been a standard joke-not-a-joke in the games industry for decades.