Thanks for sharing this PR, moin — really helpful context.
For my side project (ics_to_discourse.py importer), I actually just committed a change to stop calendar-driven updates from “noisily” bumping topics:
That commit adds some logic to decide whether an edit is “meaningful” (time/location change etc.), and uses bypass_bump plus a reset-bump-date fallback so that routine ICS syncs don’t surface topics unnecessarily.
So this PR lines up perfectly with what I was aiming for — nice to see core moving in the same direction. Once the “do not bump on edit” behaviour is merged, I’ll simplify and drop the extra fallback, but for now the commit keeps things quiet on current Discourse installs.