Considering the menu option wasn't there for a long time, and was trivially removed from the new app, I don't see how anyone could argue it was the primary purpose.
Well, considering how long they were separate and the little or no user benefit that came from merger of their app store and Amazon's other shopping app (especially post-Amazon SSO), it seems pretty clear that the primary purpose of the merged app was to sneak an otherwise prohibited app store past Google's terms, so...