Let's pretend that MMLP2 is the second coming, and it's a masterpiece, with mind-blowingly sharp lyricism, excellent production, original, innovative content, etc.
Eminem said that MMLP2 is like "revisiting" the old MMLP. That means that there will always be some minor but loud and annoying group of people saying "Dude's 40 now I can't believe he still acts like this ffs!". If Eminem went the Recovery route and tried to be more "mature", with emotional type songs, people would be mad. Eminem is, seemingly, going back to the playful, dgaf attitude that he was known for, yet some will still give him shit for this.
So yeah. The only thing I can say is, fuck those people!