Given that they're transmitting an app form over to Apple's server, they could encode checkboxes with bitmaps and text fields with dictionary LZMA. There probably will be only a few bytes of the actual data per emergency submission + protocol authentication and error correction overhead.

I'm sure the Apple use case is different from a web api, but it was more for illustrative purposes. I imagine most developers know how to wrap data in JSON and how to do a HTTP call over TLS. When using that as a point of reference, having such a transmission take a long time might show how little bandwidth some M2M networks have (or need).

I wouldn't be surprised if the current Globalstar network is so limited it wouldn't even do voice.

They support voice (https://www.globalstar.com/en-us/products/voice-and-data), it's my understanding that it's analog and not digital though, like a really narrowband landline phone call

That makes sense. Satphones are probably using that same super low symbol rate used by M2M.