Well, we do need a good OTV (Orbital Transfer Vehicle). You could use it to move stuff from orbit to orbit as needed.
So, how much fuel is this robot going to have on board? How or why would you refuel it?
The reason you put tiny fuel tanks on satellites is that it cost a lot to launch anything on a rocket. If it didn't then the engineers would put huge tanks on things sitting in orbit. Tanks designed to last as long as the next part expected to fail.
At there aren't that many kinds of propellant in use but you'd still be out of luck if you had something using hydrazine while the only thing left on the repair 'bot is nitrogen.
Orbital transfers aren't free or cheap (ask any Kerbel Space fan.) It will be interesting to see what propulsion system is proposed. There's interest in tethers for 'propelentless station keeping or orbital transfers.
Would you send up refuel cans for the robot? Would you de-orbit the robot once it ran out of fuel? Could you recover the robot to save costs, then?
Except for the Hubble Space Telescope most satellites are not designed to be serviced. What can a hypothetical servicing robot do about dead batteries or shorted out control systems or hole solar arrays on the existing fleet in orbit?
Finally, while space is pretty big, sending something on a 'soft' collision course with a dead satellite in the prime geosync orbit sounds like a great way to create more debris just where you don't want it. But it's Loral. They will have the best people Congressional pork spending can buy on staff to ask and answer these questions.