This issue makes me realise that sync target upgrades will always be quite tricky. Even if I release all the apps at the same time, there are plenty of non-official channels that are updated with a delay.
I wonder if there would be a way to notify all package maintainers in advance, and then wait for them to be ready before doing the release. I guess just a thread on the forum wouldn't quite work since not everyone will read it. @t0dd, @james-carroll, do you have any suggestion on how I could let you know about these upgrades?