The "decision" is just that now you have the option to change your email address. The headline makes it sound like this is some kind of mandatory thing with dire consequences.

You just gave me a flashback to installing CyannogenMod on a Galaxy S5 and things were either really wonky or outright broken unless a matching baseband was also flashed to match the Android version

Speaking just for myself as a longtime LineageOS user, but I have never had much luck with MMS working reliably in the stock Messaging app, I always wind up using a different SMS app and those seem to work better for me

No hate on Lineage here though, MMS sucks in general

Used one of these as a CentOS server for a few years, worked quite well once I worked around the 32 bit EFI wierdness

This is great, I still have not gotten used to the new Windows 11 context menu that moved the Properties item to the middle of the list

I might be able to help if no one else has reached out yet