And no, I don't think MIB is irrelevant and outdated. If you look around to the people who go to Universal Studios you will see that its a lot of older kids and adults that remember all of this stuff. Universal is supposed to be the "classic" side of this park and while lots of rides do need a lot of attention, they need to stay the way they are.
I hope this new attraction involves more than putting in a new movie and repainting the cars like the last time they closed this area. I'm holding out for a Despicable Me dark ride ;)