Texting 911 via satellite usually involves a relay through a private monitoring company (like GEOS), who then places a voice call to local emergency departments

Texting 911 via satellite usually involves a relay through a private monitoring company (like GEOS), who then places a voice call to local emergency departments on your behalf to activate SAR. With satellite based SOS, there's no guarantee that the local 911 can support texts, or even that there's an equivalent to 911 (think calling from Antarctica or the middle of the ocean). It's complicated and relatively expensive to coordinate - which means it's unlikely they can open this up for phones without a plan. (Compare with traditional cellular 911, which is all government funded.) The US Air Force RCC does this as a taxpayer-funded service for PLBs, but they don't support any private satellite services. Long-winded way of saying there's a lot that would need to change on the backend and funding model to make that work without being tied to a paid cellular plan.