That is a unload unused resources call. It is on a timer and has to happen sometime or memory use would keep climbing. Slower computers take longer.
Same call using same rules as A19.
Basically yes, but is the unload. Garbage collection is incremental (multiple frames) and runs every few minutes and is rarely noticed.
So I'm running a new PC compared to when i ran A19. Ryzen 5900x + 32GB + 3060Ti. I don't 'remember' there being this much a of a hitch sometimes. Though that is just that, I don't *remember* it. But if the hitch is THIS bad on my current machine, hopefully that is something you can optimize further...