I really think things will be change quicker than we think.
Why? Imagine this hypothetic situation :
-We are in mid August (for example). Vaccination is still underway for the last 20%-30% people
-The number of cases is very low, and the R metric is way below 1 since several weeks. The mask policies and some of the restrictions are eased. People starts to live as before the pandemic.
-Then we are now mid October, R metric is lower than ever. Some states have below 5 deaths per day. CDC guideline continues to ask mask for indoor, but some states are alrealy eased this policy for outdoor show with large gathering.
-By the end of the year, no one will care about the pandemic anymore (in US of course, because of the vaccination rollout)
What i mean is : i remember last year, i lived in France and for the summer and there was not a lot of Covid case through European countries. I remember the fear of the disease was gone, really. The fear came back in late September with the second wave.
When, after 1 or 2 months with few cases, few deaths, R metric below 1 (which is easy with vaccination)... how will you explain to people to keep their mask ? Even if CDC will continues to warn us about the risk of transmission (even if we are vaccinated), the pandemic will be over for some countries.
I bet countries and states will get ahead of CDC guideline quickly, under pressure from people who won't understand why we have to keep the masks and certain restrictions.
It is hard to convince some to keep their mask in a pandemic situation, it will be harder to ask to keep the mask in a post pandemic situation. The kind of situation leading to more and more extremists reactions
For now the CDC guideline is more or less respected...for now...