Yes, the original stations bought were part of a group that were originally spun off from Dumont.
That kind of begs the question about how the FOX network came to be in the 80s. I'm guessing it was Murdoch wanting a channel rather than the FCC.
Fox bought the the stations after Murdoch invested in the company. Then they decided to create a network to supply them. The FCC just licenses and regulates, it doesn't 'want' or ask for a new network or station.
However where Fox were clever is that they did the bare minimum amount of programminh that they needed to to be licensed as a network, so didn't push themselves too much. What made it the eventual big forth network was a few break through shows, in particular The Simpsons, and then the obtaining of NFL rights, which caused a lot of stations to switch affiliation to Fox