I do appreciate that software needs testing. You can spend as long as you like testing the new software, I don't especially care about that, I care what's happening to the existing installs.
So are 3CX guaranteeing SBCs running Stretch will continue to work until at least June 2022 when Stretch exits LTS?
If you're saying it's fine we've had to use Stretch for the last 17 months because it still has LTS for another 19 months, then the existing installs need to also work for that period, if they do that's fine, ish.
If there's an in place upgrade from Stretch to Buster for the SBC like there has been for the PBX (Jessie to Stretch) then that's also fine, perfect even.
If we need to go to all the sites that have had Stretch SBCs put in in the last 17 months and manually rebuild from scratch, well then that is a bit of an issue and would I feel be "in place" as far as this discussion goes..
Really we just need some accurate messaging about what we do with all these Stretch SBCs. Might stop working is a bit vague, surely it's up to you guys whether they stop or not?