Well, like I said, its a bit of a conundrum. I've heard two different stories on how it will work. One says that Air Canada's flights will be arriving in A now, which doesn't match with what I had heard before (though that was before the international concourse was a done deal) and they want a way for those passengers to not have to go through TSA as they are pre-cleared. The other said that Air Canada is going to be in B or C and everyone coming from Customs that re-checks will just head up the escalator to clear TSA.
I'm certain about the dedicated re-check room after customs though.
Why would AC pax need to go through customs or TSA at MSY if they are pre-cleared at YYZ. The pax will simply deplane the aircraft and exit the concourse or remain in the concourse and connect to another flight like any US domestic pax. That is true whether the plane is operating from Concourse A or C.
Isn't terminal A the small 5 gate terminal? Is UA planning on taking over that entire wing, or do you really mean terminal B?
There are no plans for UA to take over Concourse A. All of the international airlines and flights will be flying out of A (AC, CM, DE, BA, WN, DL, UA). The plan is for F9 and G4 to move over to A as well. There will be two gates for them to use at the very end of A, and since they have low gate usage that should work fine. Concourse A is also at 6 gates now since B is losing a gate to accommodate the addition of A.
I could see that space on B where the gate used to be as being the new United Club location. It's a good spot for it. There is also space in Concourse A for a lounge, and I would not be shocked to see something like a Priority Pass or The Club type of lounge open there to serve BA, AA, DE, and other airline business/first class passengers.