My initial response on it being announced in the Signal app was "Oh no, that's terrible!". Followed by "Meh, all software goes to shit eventually. Now it's Signal's turn". Now I already don't really care anymore.
I have been using Silence [0] as my sms app for a day and don't really miss the Signal sms integration anymore.
What bugs me more is that the text message export from Signal seems incomplete. Oh well, I will get over that as well.
(Funnily enough Silence is a fork of Signal for SMS only. I thought it looked quite familiar but just realised it is the case)