It will still be possible to send encrypted messages, just over the internet rather than over SMS. This has been the default mode of operation for a while now, we're just disabling the old SMS mode that has been lingering for the past few years.
I get that SMS leaks metadata. It's like email in that respect, isn't it?. And we still want to encrypt email. Is it so much of a burden for you people to carry the SMS encryption code? Maybe a fund-raising drive to keep it financed and included?