What's the question? I would do it again but not as a race. My friends who used the guide service in Oaxaca agreed. That way you get better food, transport, and lodging conditions.
No way I would sleep in a dorm and be stuffed on a bus with a bunch of international travelers right now. We had a flu strain go around at that 2019 race that made a few people sick and they couldn't finish the race. With Covid19? Fuck that. (Note I have zero idea what the TSN protocols for that are in 2021)