That literally isn’t true. A number of satellites had to be delayed or redesigned due to the Challenger disaster. Those satellites were planned to be launched on the Space Shuttle, and the Challenger disaster grounded the Space Shuttle for an extended period. And even when the Shuttle returned to flight, certain planned capabilities were cancelled as a result of Challenger, including West Coast launches (from Vandenberg) and the Shuttle-Centaur (an additional rocket stage designed to be carried in the Shuttle payload bay). Due to these changes, some orbits became inaccessible to the Space Shuttle, forcing those missions on to alternative launch vehicles. And switching the launch vehicle for a satellite isn’t simple, it requires redoing engineering analysis (every launch vehicle causes somewhat different stresses on the payload, so in the worst case the payload may actually require design changes to handle a different launch vehicle) and integration testing (the payload and launch vehicle need to talk to each other, and you don’t want to get that wrong, or else you can get failures like the first Boeing Starliner test flight.)

Even today, launch vehicles are shared between both crewed and uncrewed missions (Dragon uses Falcon 9, Starliner uses Atlas V), so a launch vehicle grounding due to a failure in one mission type absolutely can impact the other type too

> There’s no way that a disaster on a manned mission would affect a satellite launch. They share nothing in common.

It would definitely affect satellites, since the shuttle was a major satellite launch system. But even a deep space probe project like Voyager would be at risk, even though it seem directly related, because by affecting the political prestige of NASA, it effects everything that has to get funded at NASA – the politics of legislation are not bounded by rational direct impacts.

I’m not sure that level of confidence is warranted. What’s going to happen with NASAs funding over the next few years? Or even SpaceX?

if they used the same booster, say something like a Falcon 9, that was the cause of the disaster, anything using that booster would be put on hold until it was cleared. it just so happens the examples used very different systems, but that's not what you were referring to with your self assured declarative that just doesn't have as much weight as you want it to in modern launch systems.

Except one thing: Politics.