The Vox article refers to an Algorithmic Justice League[1] article which footnotes the TSA article that says you can opt out [2]. I have to fly next week and if I have the guts to try this I'll definitely have the TSA article handy, not, er, the Vox article.
[1] https://www.ajl.org/campaigns/fly
[2] https://www.tsa.gov/news/press/factsheets/facial-recognition...