Fauci didn't say masks and social distancing were here to stay. He just said he thinks its a good idea to carry on being cautious until we know how effective the vaccine is after its distributed. At no point did he imply they're here forever though.
“It’s not going to be a light switch” back to normalcy when a coronavirus vaccine becomes available to the public, says Dr. Anthony Fauci.
www.nbcnewyork.com
“I would recommend to people to not to abandon all public health measures just because you’ve been vaccinated, because even though for the general population it might be 90 to 95 percent effective, you don’t necessarily know for you how effective it is.”
It's a recommendation too. Of course he is going to err on the side of caution.