I’ll take that bet, passwords as part of icloud via keychain (all icloud options, including free tier) are a big selling point of the seamless “just works” nature of the ecosystem, a standalone app is basically just a GUI for that, I have serious doubts it‘ll be tied to a subscription
Maybe not that aspect of it but if there’s a way to create a premium tier that’s tied to Apple One they’ll do it for sure.
Meanwhile giant swaths of the ecosystem are completely broken. Apple Music and Screen Time for example. Both complete disasters.