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.
Good point and I’m sure they will not overlook that. I’m also pretty sure mainstream phone makers will not start making them waterproof just to circumvent this
Phones have been waterproof long before removable batteries were removed.