Yeah I heard rumblings that Tom Cruise butted heads with John Woo a bit so maybe he want's to not really remember that one
That might explain it. I'd been assuming it was McQuarrie's choice, but it would make sense if it was Cruise's preference, since he's the producer.
Aside from Luther there isn't really much continuity or purpose to it.
And Luther is a minor presence in MI2, which is basically a solo movie for Ethan.
Part 3 is when they started to reference back
Luther-The Shanghai pendulum move is going to be more difficult to crack than Langley was..."
I never noticed that. The first three films all seem completely self-contained to me.
Part 5 I don't remember any callback to previous movies.
The entire movie picks up on the tease at the end of Ghost Protocol about "the Syndicate" being the IMF's next target. Also, Director Hunley references the Langley break-in from the first film and the Kremlin incident from the fourth as parts of his case that the IMF is a renegade organization that should be shut down. And Brandt returns and references his history with the team from the previous film.