I’ve never heard of it done, but that certainly doesn’t mean it isn’t. I don’t think it’s SOP, but it’s not like I’m frequently ordering age-worthy Bordeaux from restaurants.
Personally, I would not. For one thing, part of the ‘ritual’ of bringing a wine to a table is to allow the customer to agree that it is the wine requested. Correct producer, varietal, vintage, whatever, before it is opened. It’s rare, but mistakes happens. I have had the wrong vintage brought to me, just once, when it mattered (or I thought it did anyway.)
Without knowing what particular wine you are considering there’s no way to know whether it is expected to now be at its peak, considered young, or heading over the hill. (although as a very, very general guideline, I think many 1990 Bordeaux reds are ready to drink now, while others are considered relatively young.)
If it’s considered young and tight, decanting will open it up, but personally, I’d want to experience the changes in glass myself. I think that’s certainly part of the fun of some great wines. And you run the risk of it opening up more quickly than expected and becoming too oxidized to enjoy.
If it’s at peak, it might be ready to enjoy when opened and poured, easy peasy. Again, it will change in glass as the night goes on.
Or with older wines it may have thrown a lot of sediment, requiring a cradle and a candle for decanting, which I wouldn’t want to miss either. And in many cases older wines will need to be consumed quickly after opened as they can deteriorate rather rapidly.
I like the advice given already, call the restaurant and speak to the sommelier. Ask for their suggestion and go with it.