RPGler: Maybe GOG is releasing so much now to not make it collide with Cyberpunk.
The effects of the pandemic on corporations, especially the ones that (predominantly) operate in other sectors besides game development and publishing play a role here as well, I think.
I could imagine that Sony, Warner Bros and the likes are suddenly so open to releasing DRM-free on GoG (again), just because they, in every possible way and manner, seek to recuperate their massive losses in those other sectors like in their respective film branches, for example. With the GoG releases covering only a fraction of those losses, of course, but as the saying goes:
"Kleinvieh macht auch Mist."
Horizon Zero Dawn and the just released Arkham series (although having been in the release pipeline for quite a while, iirc) could be just the beginning, and there's more to expect as long as those corporations are bleeding money, either from the pandemic or, in Square Enix's case, from yet another failed/failing live service, that still hasn't broke even on the production costs.
With "more" not refering to the brand spanking new AAA releases per se, but the respective back catalogues of older releases, of course.
Sony, for example could turn a profit by re-releasing classics from the Psygnosis portfolio through GoG. A portfolio that actually costs them money, because they have to extend/renew the rights every couple years.