I had my "Pays" mixed up lol, it was actually Google Pay (not GPay) that was getting the "old app updated" messages until the updates quit. Now I get Google Wallet updates instead, even though I never installed Wallet. I'm assuming one of the last Google Pay updates changed the name and function to Google Wallet. I've never opened either app, in fact I haven't even looked at them in my app drawer. I'm guessing the Google Pay app icon has been replaced by the Wallet icon.
I also wonder what the difference was between Google Pay and GPay?
Edit: It looks like some of my questions were answered above... but I agree Google could of made this whole thing less confusing