Is it bad if a surgeon doesn't ask for use a CT scan before revision rhinoplasty / septoplasty surgery?

There is generally no need for a CT prior to septorhinoplasty. There is nothing that the CT will show that you can't see with a headlight and/or a scope. You do need a CT for sinus surgery, but that's a different operation. Let me guess -the surgeon who wants a CT first owns his own CT scanner...

A CT scan or x-rays is generally not indicated for nose surgery, unless there is something very unusual happening such as prior major trauma, a tumor, etc. This is also the case for a lot of other facial surgery.

There's no reason to have a CT scan of the nose prior to septoplasty and rhinoplasty. The CT scan is only done when there's chronic sinusitis present with nasal polyps and you're contemplating undergoing endoscopic sinus surgery.