This is an application issue, not a brokre/daemon issue. The broker will (as dbus-daemon(1)) does, deliver all signals that clients subscribe to. If they subscribe to things they don't care about, that is something that should be fixed in the clients. During the kdbus times, quite some time was spent on fixing clients to avoid too broad subscriptions exactly to fix the issue described in that blog post.
* https://jdebp.eu/FGA/dbus-death-rattle.html