TLDR: It looks like cruising is back to pre-covid standards - more or less.
New Orleans is always a nightmare getting to the port. I realize this isn't under Carnival's direct control, but it seems like they'd have some power to get New Orleans to figure out some way to get this organized better. But once inside the terminal, things went smoothly and quickly.
I love Cozumel. Getting around is cheap and easy and their is no end of things to do. We took a cab to Chankanaab and spent the day on the beach. We rented snorkel gear (mask, snorkel, and fins) for $7 and spent most of the day snorkeling along the shore.