My read was that they're going to have 144 Gbps RF for both regular users and their ground station gateways, and 6 Tbps optical for satellite-satellite back haul, but then you can also buy direct ground-MEO access to a back haul link. (Presumably MEO-only because it's hard to maintain the link to a fast-moving LEO satellite?)

They don't seem to mention using optical for their own ground stations - maybe too unreliable?