Almost every safety regulation does this; few are effective immediately. Manufacturing plants need retooled, workforces need retrained, new equipment needs to be acquired and implemented, compliance measure must be implemented, etc.

>Except that it's already been decided the towers will be removed, which is counter to your example.

Grandfather clauses are implementation grace periods that are equal to the expected lifetime of the device. This is not counter to the example -- this is an example that sometimes these grace periods are very generous even for things we are very sure are unsafe.