I see many problems with this. I can understand what they are trying to acheive but it has as many things against it as for it. Last year my 125 blew the rear unit in first practice I had only done 2 laps and was inside qualifing time so sent the unit off to be repaired. I ended up last on times and would have been in trouble under the new rules. So what do you do? Go out again on a bike that's not fit to be ridden in an attempt to improve your speed or risk not qualifing?
It is not going to do anything to improve the entries in the classic and post classic classes either. As has been pointed out last year 5 of 17 in the big post classic class would have gone out. Imagine what would happen in you had Ryan, Guy, Olie, MDunlop all go round at 117-120 in practice very possible. Seems like a good way to kill a class before it's got off the ground.