Unfortunately the physics of this don't work very well. And at least for now the satellites are getting generational upgrades frequently, so the old satellites are obsolete. Maybe in the far future it will make sense to try this, but not anytime soon.
Pie in the sky: in the future when they have the ability to put large starship fuel tankers into orbit, they could match the orbits of starlink and have some kind of drone move between satellites and tanker.
