SImple: Vic was the first VA of Broly and he doesn't have a huge ego and a stick up his ass like Sabat or Schemmel.
They are going to hire the guy that people love AND that's going to be civil with them and not do some egotistical garbage like talking shit about Toei or try and demand higher pay... stunts that, if rumors are to be believed, Sabat and Schemmel have BOTH tried to pull.
Toei are going to back the person that's most convenient for them, after all, you'll never see Vic having another VA thrown out of a convention because "I'M the only Broly! No one else! No one has EVER voiced this character before me!"
I'm looking at you, Cuckarot.