SpaceX satellites are in a different place so the rules and limits are different.

Dish Network's satellite is in geostationary orbit. This is a narrow 2 dimensional circular ban of space approximately 20,000 miles away from the Earth. Earth sits in the middle of the circle. This is very valuable space because ~~how objects there have very little gravitational interference (rather gravity is canceled out by other source of gravity).~~ ...the satellite appears to stay in a specific spot in the sky without moving. The reason Dish Network was asked to move its old dead satellite was to make room for a new one to sit in the same place. Again, very limited space there. So when Dish Network didn't move all the way out, it means its much harder (impossible) to use that space for someone else's satellite. What's worse is that it will take from 40 to 100 years for the Dish Network Satellite to fall out of orbit on its own. So unless a vehicle goes out and gets it to move it, that slot is unavailable for decades!

SpaceX satellites, like thousands of others, are in LEO (low earth orbit). Instead of 20,000 miles away its about 200 miles from the surface of the Earth. Additionally, unlike geostationary, there's no narrow band. its all the way around the Earth's sphere. LEO is considered "self cleaning". Any dead satellites in LEO will re-enter and burn up in 3 to 5 years. As in, do nothing and LEO satellites go away relatively soon.

EDIT: @Nighed@sffa.community correctly pointed out I mixed in a Lagrange point concept, which doesn't apply here.