My personal opinion is that:
I would like to "believe" the new rules will be applied to the people falling in the related immigration routes after April last year, or somehow close to that date. Because no matter how realistic the new threshold is, people, particularly for those already in the fourth year (including myself), have no chance to increase the incoming to meet the requirements. It does not matter the capability we poses, just in short of time. I have to say, it is unfair. I don't care if I can obtain ILR 4 years ago. But now, I think it is a difficult dilemma for me.
If you just started career under the category of T2, or similar routes, a four-year space is sufficient for you to think about whether to stay at this country, or simply move to other places.
Again, it is just a personal opinion. And we have no point to argue with anyone since no official announcement has been made by now.
Finger crossed