Real talk, the changes aren't that big of a deal EXCEPT for the weapon switch speed. The ability to combo the flare gun or shotgun with the airblast was one of pyro's only real dm capabilities. Yes airblast was stupidly broken and it's good that that part of pyro has been nerfed, which honestly should be nerfed even harder, but taking away the weapon switch speed was uncalled for.
Nerfing the worst class in tf2 (I'm looking at this from a highlander viewpoint) and making it even worse at doing one of the few things it can do isn't justified.