https://stackoverflow.com/questions/28755825/android-app-naming-guidelines-first-word-as-company
This seems to suggest otherwise.
The reply from Google is that this guy couldn’t name his app “xkcd Viewer”…he had to name it Viewer FOR xkcd…
So no, it wasn’t Reddit who made that change to apps, it was Google, as I correctly stated.
They may have been around the same time, but I still very much remember reddit being behind the change to distinguish the official app