It seems to me they would fill FO E175 vacancies almost exclusively from the ranks of new-hire classes. But that would be luck of the draw. One class might be for the CRJ one month, and the next month for the 175. I seriously doubt they're going to allow movement between the two airframes - too costly.

To staff the Captains, I imagine they would put it out for bid and senior FO's with the requirements met to upgrade, would fill those slots.

If this is the case, it strikes me that the airplane will be very Junior.

Our current contract puts a 3 year seat lock on all new Captains, however, this really was only applicable when we had ERJs on the property. It kept ERJ Captains from bidding over to the CRJ until the 3 years was up. CRJ captains could never bid to the ERJ because it was considered lesser equipment. I believe we still cannot bid to lesser equipment. At best the 175 is "equal" equipment, but since it will not be higher paying, I bet they will consider it lesser, and won't allow much movement from CRJ to 175.

Like in the old days. The only way to change airframes was to either upgrade out of it, or move to higher equipment after the seat lock, or get your airplane parked out from under you.

That said, for the sake of getting the movers and shakers into the new airplane to keep United happy, or because of inability to otherwise staff it, I wouldn't be surprised if some of this was relaxed at company discretion. I'm sure it will all be spelled out if and when it happens.