Congress can do pretty much anything it likes - within the Constitutional powers, of course. But FCC can't make regulation that Congress just shut down again, at least not until the Congress changes its mind. Otherwise it'd be useless for the Congress to intervene at all - Congress shuts down one set of rules, and then FCC enacts another one which is pretty much the the same? Of course, if Congress changes their mind they can pass legislation that enables FCC to make such rules again.