Cable isn’t regulated by the FCC.
I'm not an expert on the subject, but that doesn't sound right as a broad statement. I think some of that depends on whether you're talking about cable carriers (the companies whose services the ordinary viewer would contract for, like Time Warner, for instance) or the cable channels and networks (like FoxNews, CNN, ESPN, CNBC, etc., etc.). I know that the cable carriers are largely regulated by local governments, but I also know that the FCC has to approve of mergers and acquisitions amongst them, or at least that was true during the Clinton years. The guess here is that the networks, like FoxNews are licensed by the FCC as well.
Regardless, Murdoch's NewsCorp operates a whole slew of over-the-air Fox Network television broadcast stations, with outlets in just about every major market in the country. Those definitely do require FCC licensing, renewable periodically. So, he has a lot of skin in the game, no matter what the legal status of cable regulation.