I currently have a valid B1/B2 visa until 2029.
I originally arrived in the USA in December 2019 for a non-employed ski season. After the lifts closed I looked out the window at the national park and decided I was going to stick around. I applied for an extension, but left (end of July 2020) before I received a decision (I was assured by CIS over the phone that this wouldn't be an issue on my next entry provided I arrived at the border with proof of my application). I'm hoping to try the ski season again and arrive in late November. I'll have been out for ~115 days, but whether or not this is a meaningful departure etc. I think is outside the scope of this question, I'm just providing context in case it suddenly becomes relevant. I'm currently resident in Austria.
Based on the various proclamations (https://travel.state.gov/content/travel/en/News/visas-news/presidential-proclamation-coronavirus.html), it's my understanding that if I spend 14 days outside of one of the name countries prior to my arrival (e.g. the Caribbean, Colombia) there's no Covid-19-related reason why I wouldn't be granted entry to the USA.
The FCO (UK foreign office), had this to stay (https://www.gov.uk/foreign-travel-advice/usa/entry-requirements):
Our understanding is that British nationals currently in the USA on one of these visas can depart and enter as long as their visa is valid – subject to other rules.
I was in the USA at the time of the proclamations and my visa is still valid. Are there any "other rules" that I have missed?