It's reasonable that they would still have USB-A. Think about customers that will complain about not having USB-A, versus how many people want the ports to be USB-C only. I would bet there are far more people in the former category than the latter. And for data-only USB which is what the non-Thunderbolt ports on this are, as long as they're gen 2, the speeds are the same between C and A. So people will largely either not care it's not type-C only, or they will be bothered if it's type-C only and want it to be type-A.
It's different than Firewire because the FW protocol itself is outdated and largely gone from consumer devices, but USB is still the same protocol as always, and this one supports 10 Gbits on all USB ports so it's no downgrade to be type-A. It'd be nice if there were more Thunderbolt ports but on hub mode you're limited to 3 Thunderbolt hub ports (you connect up to 6 Thunderbolt devices through daisy chaining combined with the hub capability, but only up to 6 in total).