""Oh, it'd almost definitely be a transfer of the West End show? I wasn't aware of that. Staunton is a good pick for the role, but I'd fear she isn't well known enough on this side of the pond."
1. It's Gypsy. That alone can get people in the seats.
2. They can sell it using Staunton's ties to the Harry Potter films...People would recognize her as Delores Umbridge. "
The last two revivals of the show beg to differ with your first assertion, both of which failed to recoup, with the most recent revival closing even earlier than originally planned. So, despite the great, and very much deserved, love for this piece amongst the theatre community, it's not a guarantee that the title alone will fill seats.
Imelda Staunton has stated that she has no desire to do an extended run of any show in NY (if I recall she stated this when there was talk of Sweeney Todd possibly transferring). So, unless she has had a great change of heart, you would be looking at a very limited run that would require an absolutely insane, probably near impossible, recoupment schedule. Even if they could convince her to do the show for six months its hard to imagine a recoupment schedule that could be feasible for that time, unless the show looked even cheaper than the 2008 revival.