A couple thoughts...

1) Interesting that the mystery TripAdvisor poster has the same writing style, grammatical errors, and unique line break structure as the completely-unrelated FT poster here. Also interesting that said FT poster was so moved by reading this one, unrelated TA review that it inspired them to take up this stranger's noble cause and champion it here. Hmm...

2) Yes, restaurants play this game, yes it's annoying. Sometimes it is legitimate - there can be no one in the place at 630 but they have a bunch of reservations at 730, etc. Hosts can always do a better job of communicating. OpenTable adds complexity because it's a third party - my understanding (anecdotally, not having worked in a restaurant) is that there is not always complete transparency between OT and the restaurant front of house in real time.

3) Not really sure who would have more power in the relationship here, the hotel or the restaurateur. This place is a Voltaggio establishment, so honestly they have quite a bit of clout. Also don't know the relationship as to who owns the building versus runs the hotel and restaurants; there could be some complexities to the legal structure. They may just all be co-tenants; the restaurant might not be structurally subordinate to the hotel.

4) Either way, if I was staying at a hotel and wanted a seat in the restaurant, my first instinct would be to call the concierge, not initiate a strange cloak-and-dagger game using OpenTable.