They added 2 types of rockets.
One is the ordinary guided rocket shot from light tanks (BMP-2, Bradley)
SAM tanks now shoots their own type of rocket, more like a missile.
Its much faster than the ordinary rockets, and it automatically explodes when the jet is near by.
Its pretty much a suicide action to fly straight to the SAM vehicles after the update.
Fly towards your target from a decent distance, spam 4 rockets and turn imminently to escape from the missiles :)