It looks like they put the ice into the Delta Center for the press conference today (5:00pm MT)...
https://twitter.com/user/status/1781095363417723322
It appears they lose about 2,400 lower bowl seats in the conversion from the basketball to hockey configurations. If they sold the upper deck obstructed view seats, they could potentially fit 16,000 in the building.
They could put some seating at ice level in the corners (similar to what the Isles did at Barclays) to add a few hundred seats.
Bettman said there's a plan to get 17,000 unobstructed seats into the building, but I don't know how they can pull that off.