"This feels like a "because they can" scenario."
Because they HOPE they can. Let's see what the EU's answer will be.
I can certainly agree for a fee to Gmail, Maps, Youtube. Why not, they're applications without direct income beside ads (I'd rather have them available optionally to the end-user to choose and pay if they want, but okay).
Play, though? They're skimming 30% of sales there. They'll have a harder time explaining it's also a money-losing operation that has to be bundled with the others.