Probably you will need a backend to move the id to another device.
My games use backend generated IDs and while the idea was interchangability between devices (you could even mix between Android & IOS) to keep scores in sync
without the need for an email, login/password but they didn't like it either.
They thought it could/would be used to assign/add features to the app bought outside of their cashing system (read losing their 30% cut).
It's still there but hidden and still reachable just in case someone needs it.
So yes they are more picky since 1.5 years as it was no problem for years before.
Some lady even called me to force me to use their leaderboard stuff which sucks major and is too limited (and easy to hack/cheat).