Yes, it is a large gathering. There's also irony in that he is pointing it out while being physically present as well.
It's a called self awareness. People laughed because they recognized the irony of the situation, but were well aware of the risks and mitigations.
Everyone was required to have proof of a negative test, vaccination+boosting. That's about as much as you can practically do.
This wasn't "you can't take muh freedoms"! Or "I was born free, I'll die free (by being ineligible for a life-saving organ transplant due to refusing the COVID vaccine)"