The most notable change seems to be the expectation that members post reviews
The wording of the rule is important
"Members that do not contribute Reviews or where their accounts become dormant
may have their membership revoked."
That wisely allows discretion on an individual basis ie judging a member's overall contribution to the forum.
I think (but could be wrong) that it is aimed at members who, from their posts, are clearly active punters and who for example ask for specific info but then give little back in the form of reviews and that they are the main target.
This allows discretion with say retired or inactive punters, who wish to continue to be involved but of course if their accounts become dormant may then also be deleted.
In terms of dormant accounts huge numbers of people join forums and only ever logon once or sometimes never at all. Then there is the issue of those who logon regularly but never post!!