The funny bit is that the example from the video requires a companion device in order to actually have something to send, since it doesn't have a keyboard or microphone, and the natural companion device for that in a mobile situation would be ... an Android or iPhone.
That said, it would also work paired with a tablet and maybe it can just be paired with a bluetooth keyboard (the hardware in it - specifically the ESP32 - has bluetooth support built-in, so it depends on the software)
Mind you, this is only a limitation from this specific implementation (which is basically a gadget for electronics hobbyists hence no built-in keyboard), not from the LoRa stuff itself.
You can take a look at the meshtastic project - https//www.meshtastic.org - people have made some pretty wild solutions, it's pretty cheap to build too.
I've got an order pending while I decide which setup I want to play with first - but I have a feeling I'm just going to go with one portable and one to leave in the office, and go from there.
Regardless of it's potential use for protests, it's a fun project!