Alternative take: if hotel projects don't pencil out financially on terra firma sites next door then they certainly won't pencil out here. Even with the deck in place, it would still likely be much more expensive to build on this site than plenty of other alternatives in the area. The deck is close to a sunk cost, so why put good money after bad?
This entire project has always relied entirely on it being to command astronomical rents once it hit the market. There was a narrow window in the late-2010s/early-2020s when that looked possible -- and hence the development -- but that window has closed.
It pains me to say this, but I have a very hard time seeing this move forward in the foreseeable future.
I agree this is going to sit until either market conditions to build improve (unlikely before 2028) or the developer sells to recoup whatever they can and someone else takes a swing after getting the deck and air rights at bargain basement prices.
The only way this might end up making sense is it can be redesigned for more height but that may be structurally impossible.