Truth Tobias with Key things like changes in TOS, Privacy type things imho it should email users that this has had changes or at least notify users on logon it has changed. Much like when someone edits a post they are not the owner.
Especially in places like the EU where things can be very tricky with there compliance laws.
I have for example seen cases where a staff account makes a sweeping change then uses it to ban or silence users.
A discussion platform should inform users if the TOS & such has been modified. Especially as most might just skim it once.
Now sure I agree an Announcement Category for example a good host could ensure this info is passed along to all. But then you need a a good structured team running things that know this needs to be advertised.
When most social platforms make changes to TOS, Privacy a notification id generated to notify the clients of changes.