It had been in the works for a while, but now it has formally been adopted. From the article:
The regulation provides that by 2027 portable batteries incorporated into appliances should be removable and replaceable by the end-user, leaving sufficient time for operators to adapt the design of their products to this requirement.
It’s not just support. Companies like Google and Apple can do a lot to pressure third party developers to remove compatibility for older versions.
This includes:
limiting compatibility for new versions of the API. So if you want to be compatible with the latest Android/iOS version, you have to drop compatibility for older versions.
make the newest version of the toolchains incompatible with older versions of the OS.
In Google’s case, they can mandate things like SafetyNet, which directly targets the custom ROM community.