Quote Originally Posted by rappa View Post
The reason to nerf those primal was they were necessary to kill to get the access to new primals extremes.
Only because that's the choice SE decided to make. There's no intrinsic reason they couldn't have left that requirement off and not enabled echo, as demonstrated by the fact that they did eventually remove that requirement.

They could also decide to make an A4S kill necessary to enter A5S, in turn making it "necessary" to enable echo for A1S-A4S.