LoRa is just a transport layer. You can do whatever encryption you want and LoRaWAN has some basic encryption built in. It's hard(er) to triangulate if you don't have constant traffic (like route updates in mesh, or heavy concentrated users like at a concert or protest), but be aware that AWS sidewalk (and all the alexa devices fielded in peoples homes, etc.) run LoRa antennas and traffic. So in the US, Amazon could do a reasonable job at triangulation of frequent emitters. In China and EU there is infrastructure in place (5G/SDR stuff overtly) that can do a pretty good job at triangulating a wide band of RF emitters.

Meshtastic is not really designed to avoid that, but more for resiliency and off-grid type scenarios. Your best bet of really avoiding triangulation by state or telco level infratructure is to get creative with frequency and even transport layer hopping. None of which is really consumer friendly.

[edit-to-add] another tactic to for low probability detection is to hide in noise on high traffic channels. basically figure out what their filter sensitivty is and see if you can go below that threshold and still maintain coherent channel, etc.