the things that are new trends for you are things we have already done and we have moved on. to be "on" something is to be currently doing (or liking) it. to be "off" something is to have moved on, to not be doing it or interested in it anymore.
Jay-Z may not have any specific complaint about talkshow host Rush Limbaugh's opinions of rap music, but since he is a prominent conservative figure he is grouped with Bill O'Reilly who angered Ludacris, one of Jay-Z's friends, and therefore disliked.
Jay-Z is asking someone to speak to talkshow host Bill O'Reilly on his behalf. He wants O'Reilly to stay out of the affairs of rappers and not to criticize them or their music (Bill O'Reilly had a feud with rapper Ludacris which he raps about).