I didn't find a quick # of lift capacity of Falcon 9 to LEO in reusable mode, but SpaceX has stated >= 60% capacity in reusable mode. LEO in non-reusable mode has about 23,000kg, so there could be a fair bit of headroom for extra mass in LEO reusable mode even with 48 starlink sats. Admittedly, probably not enough to really change the magnitude of the GGP's calculations.
I didn't find a quick # of lift capacity of Falcon 9 to LEO in reusable mode, but SpaceX has stated >= 60% capacity in reusable mode. LEO in non-reusable mode has about 23,000kg, so there could be a fair bit of headroom for extra mass in LEO reusable mode even with 48 starlink sats. Admittedly, probably not enough to really change the magnitude of the GGP's calculations.