He did it to get someone's attention for sure. It's like Trump's stand back and stand by comment. MAGA makes these comments, gestures, "jokes" etc. in a way that they can deny intent while getting their message through.
But in this case, the claim is that everything we think of is real is a Matrix-style illusion. Science is about rigorous testing of refutable hypotheses by empirical evidence. If we can't trust our senses, empirical evidence goes out the window and science along with it. Fauci was basing his claims on science, and the "they" who were challenging it were anti-science crackpots. Right, published in a popular science journal instead of a peer-reviewed publication.
I saw it and doubt it was intentional. More like the Strangelove reflex from excitement that his guy won. Not necessarily NAZI, but the Roman salute.
And now RFK Jr. has been sworn in as Secretary of Health and Human Services. An eccentric (to put it mildly) anti-vaxxer has been put in charge of our health care. Yet another inmate running the asylum. Trump wanted him and once again Trump got what he wanted. If you need a vaccine, an operation or any other health issue dealt with, do it now before the system is gutted!