warning: pyro main opinion
imo the airblast changes were good except that the push force is a bit too much. It's very easy to a) send a bombing soldier/demo to Narnia with one airblast b) get tons of environmental kills in maps like upward. But it's good that airblast can't be used as an aim assist for free shots with the flare gun or shotgun. As much as I enjoy the flare gun in particular, it often felt like as soon as your average degreasermain pressed m2 on you in a pub you were a goner, and it's not the case anymore.
TBH it's made me enjoy the flare gun even more even though it's one of the worst pyro secondaries now, you can use a lot of different ways to aim it. Either you suck it up and hard aim without airblasting ('flarepunch'), you push people to corners if there are any, or you do what TMP said and aim m2 at the ground to pop them up.
I don't think anything about pyro will be changed in the foreseeable future, but toning down the push force would be just about perfect imo