Your cell phone uses the nearest base station, the base station will handover to the satellite infra.

Why do you need satellite if you can connect to a base station? This makes no sense.

No, they claim direct phone to satellite link.

No, that’s just satellite backhaul for a cell tower. That’s not hard, but also typically if you can get power to a base station you can run fiber along the same poles the power runs on.

This is direct from handset to satellite, it’s clearly explained in the link.

Aren't those satellites going to generate simulated cell tower signals so you won't require any modification whatsoever?