You didn't near this from me...
Signal has been working on encrypted clud backups for quite a while. The hopes were that we would see this come to frution at the end of this year, but Meredith Whittaker has just dashed that.
Word is that the current ETA is March 2025. This won't impact local backups or selfhosted backups, but will fix one feature request that has been asked by many over the last years: cross-platform migration (eg, facilitating iOS => GrapheneOS).
A lot of additional details remain to be seen. It is likely that Signal will offer the cloud (in addition to). Only time will tell. But the cross-platform migrations: whoohoo!