I may have misremembered, it may be an hour after they woke up, for example. I would also imagine each individual animal is assessed individually, from what my vet was saying.
I personally am not comfortable with it. I've never syringe fed after a GA. Ever. My bunnies have always eaten satisfactorily fast enough. I have good tricks that work for mine and we employ them.
In my view, for my bunnies only, if they are well enough to be syringe fed, then they are well enough to be home. They tend to let my bunnies come home earlier than most, and I would prefer that. I can do any other necessaries at home, although have never yet had to.
I'm also one where I don't expect them to eat at the vets. My vet also says it's vital to get them home ASAP to get them eating ASAP.
Butterfly had a dental today and he was eating here before the time they initially suggested I collect him, and I know he wouldn't have been eating if he had been there.
It's a new procedure (that and giving Sub cut fluids to every rabbit who has a GA- I'm very in favour of this- both things that one of the vets was recently told on a conference) and I think I'll discuss it with my vet as to what to do with mine.