Remove the CPL requirement for instructing and you'll still see the same level of flight instruction from older and more experienced PPL's, possibly better, who's to say?
The problem of where the hours builders will go is of no concern to the CAA in my opinion however, the airlines may find they need to lower their entry requirements, at least until the multi-crew CPL comes to fruition at which point there'll be little problem for either camp will there?
No instructor shortage during winter months tho that's for sure. I'm bored !!!!less.
VFE.