What deadlines did you have in mind? Are you intending to offer this as a
"first-class citizen" option in bullseye? When dbus-broker has only been
in the archive for two days, that doesn't seem like very much testing
to have confidence that it will be suitable to provide important system
services through the 3 year lifetime of bullseye.
I think it's fine as an optional package that users have to opt-in
for. Nothing depends on it, so it won't be installed by default
anywhere. Also there's no config to do to switch - install or
uninstall.
Also there's no difference to what Fedora shipped for a couple of
years now - we got no patches, special build flags or anything. So
it's good enough to be in bullseye in my view.
I'm not a Debian developer nor a Debian maintainer but I think I see
what Simon said. People trust us to provide working packages for
which we had enough testing.