I don't understand your second point. Public Sans isn't in OS/browser font stacks, either. What makes its inclusion more likely than, say, a 15 year-old open source font like DejaVu Sans?
I took the parent comment to be saying, "look, there are all these preexisting sans typefaces, why not just take one of the ones on this list". The answer: because they'd have to arrange to pay, and to source them from the commercial services that make them available.
I agree that there are other typefaces they could use! I was mostly commenting on how a list of faces that includes Avenir, Univers, and FF Meta was probably not the best summary of the available options.
I agree that there are other typefaces they could use! I was mostly commenting on how a list of faces that includes Avenir, Univers, and FF Meta was probably not the best summary of the available options.