Rules like this dont need to be enforced (or even enforceable) because by and large the community is onboard. Ie if Canlis, a Seattle institution ,was seen as looking for loopholes and risking lives it would be the end of their entire business.
I didn't mean to suggest anything nefarious. On the contrary, I'm curious as to what kinds of "fun" and "social" celebrations we can do these days while still limiting coronavirus risk.