Support is typically low paid because it's a lot of effort for little reward, no matter how much you pay someone in support, there's only so much impact they can have on the bottom line. The organization as an organism where every organ is as equally important as the other is a beautiful sentiment but the appendix is getting jettisoned at the first sign of trouble. Support, no matter how valued and important to the organisation it is, is never worth $200k/year on the output of 1 person.
The exception to the rule for sales is the canary in the coal mine: sales measures itself, but every role can (and will) be measured when the pressure is on, there will be competition for budget, and the support team will get squeezed until they're empty while the engineers coast. I would be more convinced that this model could survive outside of the vc bubble if sales had bought in to too. Sales as a competitive sport is cultural, not fundamental.
Anyway, not criticism, just musing, love that they're trying it, even if this doesn't work out, everyone had a few good years, it's worth a shot.