This isn't hard to achieve - I think a Starlink-guided drone army is pretty much unjammable - unless you have space based jammers, but once they get laser datalinks it will be 100% unjammable.
The satellite adds an extra vulnerability. You can see the satellite from 1000km away. Just build a big directional antenna well outside the war zone.
Jamming signals in a war zone is hard because you give away your own position when you start jamming.
Ground based jammers are physically not capable of doing this. And I'm pretty sure they use frequency bands that do not reflect off the ionosphere otherwise they couldn't talk to satellites.
Secondly it’s probably easier to jam the satellite, because you know exactly where it is.
If you’re on the ground near the drone you can definitely send noise at the satellite so it can’t receive anything from the drone.
You’d have to do some testing to see if a jammer off to the side (1000km away) works. I think it will.
OISL? How many of them do you expect each Sat to have?
Probably you could control a good amount of drones with a single satellite transciever, and your typical drone would have LOS to many satellites.
There could be multiplexer drones whose purpose would be to mediate between cheap disposable small drones and the satellites themselves.
This is already a thing (not with lasers and sats) - the Russians have the Orlan drones with sophisticated(ish) surveillance equipment that act as spotters and guide the Lancet suicide drones and artillery