As a former Bostonian, I will say that that bus won’t fly there.
Although as both a genderqueer person and really nitpicky communicator, I think that people need to be careful how they confront stuff like this. The bus’ message is that sex is biological, which coincides (to a degree) with what gender studies and activists teach, along with the distinction between sex and gender. But the bus is apparently being decried as anti-transgender.
This can put gender activists in the position of appearing to contradict themselves, if they aren’t very clear. It was a subversive calculation by those who commissioned this.