In a real scenario these things work. Please don't fall into "what if's" which are exotic and confused as things bigger than what they are.
I've always been interested in helping folks that help folks.
I started looking at Meshtastic, some years ago, but found the ecosystem to be a bit overly-complex, as is often the case, with "Swiss Army Knife" approaches.
It is true that you will not be able to jam the _downlink_ frequency outside local areas.
But due to the FM capture effect, anyone else in the same hemisphere with a basic 100w transmitter (and appropriate antenna) on the _uplink_ frequency will be able to deny the satellite service to all the 5W Baofeng radios that preppers are stockpiling.
Look: if someone is jamming something with a 100 watt transmitter which causes impact on the adversary, that location is quickly bombed because it is now a giant beacon that advertises its position.
I'll even throw a cheap appeal to authority and mention that I've done this stuff professionally in the military for a decade. I'll still trust more on the usability of my cheap walkie-talkie capable of +50km range and satellite texts than an exotic LoRa used on the ground by few internet warriors.
In either case, jamming is a possibility.