My feelings on this are:
I don't condone the use of the word. Has Eminem matured since the likes of the MMLP, well yeah obviously, infact Recovery was a far cry from any of his earlier work but let's not forget or try to make out the likes of Stan and Sing for the moment weren't mature pieces of music either, they were.
His album before Kamikaze, Revival (which I didn't enjoy that much as an Eminem fan) was actual so mature it got fucking panned because people moaned that we don't like this new Eminem we like angry Eminem blah blah. So he thought fuck it and one of those people was Tyler the Creator. Tyler liked Eminem' s and D12's music, he went on tour with them, they were cool then he dissed Eminem' s music, that's a little snake type shit. Eminem said he worshipped there balls, he's sacrilegious. So he's making fun of him there. But you gotta understand that when it comes to insults in the rap game nothing is off the table, not race, not sexuality not nothing. Anything can and will be said to offend you.
That's the nature of the game, the rap game isn't based on sympathy, or it wasn't. But the rap game isn't what it used to be.
Also if you've actually ever listened to Eminem' s music since day one, he admits to saying this shit just to piss you off, just to fuck with you. Once again it's working.