Actually, The Late Great Bird of the Galaxy sold his right to Star Trek property to Paramount a long time before Berman came along (can't recall the date, but I'm sure someone here knows). The fact that he is the creative genius behind it that Paramount employs him to work on Star Trek. Of course, Paramount couldn't prevent Roddenberry's deteriorating health. So Paramount had to find a successor to the Star Trek franchise. I don't know if Berman and Roddenberry have gotten along during the TNG series, but it does seems that Roddenberry pretty much give him the blessing.