Ahh, I was not aware of that, in light of that it seems like dropping encrypted SMS support was premature. (Here I don't think there's any places with non-data coverage, though there is now some of the opposite - places with no circuit-switched voice coverage, voice there is only through VoLTE).
Also note that as it stands encrypted SMS is technically superior. This is Moxie's comment on GCM-free Signal:
> I expect it to have high battery consumption and an unreliable user experience, but would be fine with it if it comes with a warning and only runs in the absence of play services
You don't get high battery consumption, or unreliable user experience, or a requirement for Play Services with pure SMS encryption.
SMS encryption is actually quite a tricksy problem. TextSecure's entire purpose (over bog standard IM OTR) was to solve it, providing individual message-level forward secrecy. This is why it's so perplexing to me that they dropped it (I understand that part of the reason is that iOS simply does not allow it)
