Others default to Signal, not SMS, after uninstall

This bug means that when somebody uninstalls Signal (or an iPhone disables it for lack of use), people sending messages never learn that the message didn't go through.

As a result:

  "I just missed out on placing an offer on a house because of this issue."

  "Today I ended up uninstalling Signal after an experience where this problem caused me to almost lose two of my friends."

  "I just had the experience of being very worried about a friend's well-being because he stopped responding to my messages."

And so forth. It makes Signal a very risky thing to use, not because the encryption is bad, but because the UX is. It seems easy to fix, but Signal never seems to care.