Meh, yes there is wiggle room, but it is so minuscule...
The thing is if it was retrieved pre-fire, wherever it is, it would have to be maintained, or it would be relatively useless today. Yes it would be better than starting from the ground floor, but without the protection of a sanctuary like Harry's and continual magical maintenance, all the magical "conduits" are probably washed away by all those sunrises, and the general evolution of the city would have rendered it an inaccurate thaumatlogical (however we spell it today) link.
I feel it is less likely that it will be restored to Harry than his old shield bracelet (which is a non-zero chance I'll admit). I think there is a higher degree of likeliness that if it still exists, it will be in the hands of an antagonist who is using it for ill.
I think we have precedent that if a Fae were the one who pulled it from the lab, they would be metaphysically obligated to return his "property" and they haven't