If Othellos testicles have descended, he can actually be done now, though it does depend on what age your vet feels comfortable doing them of course.
Have you a rabbit experienced vet? One way we can tell is if they advise you to fast the rabbit before surgery. If they do, then this is NOT a rabbit savvy vet as rabbits should never be fasted. Sometimes an uninformed staff member may give the wrong advice based on cat/dog protocols so if you get given the wrong info, check that the vet themselves are in the know.
I just read in your bonding thread that your 2 were recently put together. You’ll just have to keep a close eye on them after his surgery. As karla said, sometimes post-neuter they can actually act more hormonally driven for a short time. This could cause Othello to chase and want to mount. So the risk is he could open his surgery site, or Calypso could fight him. So I think the best way forward is to keep a close eye on them. Since their bond is so new, if you do have to separate them all is not lost. You’ll be able to patch it up within a week or two.