They must all really not want you showing up anyway.
The whole "you can go out masked" part from the CDC sounds fishy to me too. And, it assumes people do it right and don't just read it as "you can go out
masked".
I read a twitter story recently of a parent (an infectious disease doctor I think) getting a hard time from their kid's school for not sending them back on day 6. The parent was telling them "the at home test is still bright red 2 lines" and at first the school was like "sure, just send them back it's been 5 days". The school talked to someone more exciting and agreed that the kid should stay home until the test didn't show positive anymore.
I think the trend here is, the CDC and general guidance is concerned with preventing the healthcare system from collapsing. It doesn't really care about an individual, just the system. So, as long as an individual isn't going to crash the system, it's all fine and just "whatever".