I also enjoyed MiB 3, and it was one of the few films I saw in theaters last year, but I don't think there's anything from the third film specifically that could be added to the existing ride. Also, they can't pull a Spider-Man here, where they can advertise upgrades and a re-opening of the ride. There's not much they can do to the ride, unless they completely overhaul it.
I do hope they refurb and polish all the ride's elements, and I know they eventually will, but obviously it's not a priority. This ride isn't the most needy of Uni TLC, plus they got a lot going on with TF:3D, Springfield, London, and all the rumored projects that may be coming.