Of course Vince McMahon knows about TNA. They are the second biggest wrestling promotion in the US. He knows about ROH, too. Anything below that is doubtful.
Now would he buy TNA out if given the opportunity? Possibly. But it would be the same thing as WCW except for the whole Invasion thing. Take the guys you like (which is basically Joe and AJ) and put them on TV, give the rest development contracts or release them to the indies and keep the tape collection.