It's hard to tell. There's indications it's meant to work on any form factor, but at least initially their focus seemed to be on desktop-esque hardware like the Intel NUC, an Acer slate tablet that runs x64, etc. and then with the Raspberry Pi for ARM support. There hasn't yet been a clear indication that they're working on phone support for it, or when that would be.
It's still super early for Fuchsia though, so it's anyone's guess.
I agree, it's still early and there's not much info at the moment. Still, in the maxwell repo, there's mentions of "GPS acquirers" and in the SysUI repo, there's icons for battery, airplane mode, screen rotation and cellular signal.
Nothing really specific for phones since these things can be found in some tablets and laptops, but apps in Fuchsia are made with Flutter, so it's interesting since it was made to make cross-platform mobile dev easier on Android/iOS.
It's still super early for Fuchsia though, so it's anyone's guess.