We re-caulked before
polishing. Two reasons:
1) we didn't want old loose caulk getting in the buffing pads which would cause scratches during polishing
2) the compounding "goo" would get in all the seams and have to be cleaned out before caulking if we waited until after. If not totally removed, the caulk wouldn't stick and leaks could develop.
Although others have done all the caulking after for their reasons too...it's one of those
questions, as many answers as people you ask.
We also removed all the old caulking we could with popscile sticks before re-caulking.