Is there an official announcement we might have missed?
(The deleted message was me. I’m trying not to launch into a frustrated rant here.)
I've been searching and haven't found anything.
Personally, it seems more like a bug, since the page displaying the ad always does, while others never do.If it were due to a policy change on Itch, the ad would appear randomly on any page, and that doesn't seem to be the case.