I also hit the issue, it was trivial to get a new esim from the provider but not being able to transfer was unexpected and annoying (as I had to emergency go an

I also hit the issue, it was trivial to get a new esim from the provider but not being able to transfer was unexpected and annoying (as I had to emergency go and hunt for a way to renew). It added frustration to the phone change, especially as esim transfer is straight up part of apple's migration assistant so I can only assume when it works it's seamless.