I think you haven't seen how notification bar of a typical android user over 40 looks like. It's usually 3 meters of random application bloat, music/movie/audiobook ads and three different weather widgets.
Digital hygiene is something only a very small percentage of users follow, so such ad might as well work while surrounded by 5 other ads
I really hope this will just replace the update dialogue, not add another one on top of it. Manually tapping "update" for all Fdroid apps is a huge slog already