Well, the problem here is not only in the version downgrade, it’s in me not understanding that the Haiku package would depend on an explicit version, and doing the update to Noto before going to sleep, leading to a 24 hours delay before the fix.
SoftwareUpdater always does a “full sync” and has no problem downgrading packages if the repositories say so. So, if done correctly, there would be no problems for users.
Also, such versionning scheme changes happen rarely enough that it’s not a high priority thing. The “epoch” field could be added if soemeone wants to contribute a patch adding it, but it will be in addition to the version and revision, and that make things more confusing than they need to, all the time, to fix a problem that only happens very rarely. Is it worth it?
The Haiku package was fixed yesterday, updates with SoftwareUpdater should work again. For those of you using pkgman, remember to check pkgman full-sync from time to time to see if it does more updates than what the simple pkgman update does.