Agreed, it grew way too out of hand to be merged less than 24 hours before the deadline. And I agree with @elextr that it likely requires more testing than just hoping every other distro is shipping a well-behaving theme (better behaving than Debian's Adwaita 43) by default, although @techee has a point that as the icons that please Adwaita are used by GTK itself, it's *likely* not to cause much trouble.
Anyway, on top of this some of the changes here I'm happy with, some I am not so much (as mentioned in the commit messages), so it's not even like it's obviously the right thing to do down the road.
Let's just cross fingers and hope Debian does something about it, and nobody else is shipping a broken Adwaita icon theme… or that none of our user actually use the broken ones. :crossed_fingers: