Why would you not? Tesla is sending even the infortainment data stream through that bus. It's incredibly helpful having all data travel on a singular wire because you can tap in at one point and read it all out. Makes the entire system significantly easier to debug, understand and develop against.

10 Gb/s is not all that much for cameras. Enough for one 60 Hz 4k 14-bit depth camera transmitting raw bayer data.

60 Hz * 3840 * 2160 * 14bit is 6.96 Gbps.

FSD will benefit from high-resolution (4K or above) camera feeds (for things like reading signs and detecting small obstacles). You can do this in a 10Gbps network and have tons of headroom for every other function the car will perform.