Hi,
I assume you would still want to show the link to users who actually do have the right to edit.
Yes, that's it.
How exactly could that be abused? CSS rules seem the best approach to me.
First I thought on introducing something like `.myclass{display:none;}` in [[MediaWiki:Common.css]] and `.myclass{display:inline;}` in [[MediaWiki:Group-autoconfirmed.css]], but this would let users freely hide arbitrary content from newbies on any Wikimedia page (Wikipedia articles, user pages, etc.) by using <div class="myclass">...</div>. Although this permission hierarchy would be theoretically correct (trusted users would see more things than newbies, not the opposite), we probably don't want to offer this "feature" by default with the solution to T207648. On the other hand, this would only solve the task of identifying when a user is autoconfirmed.
However, I like https://phabricator.wikimedia.org/T207648#4701665, which would combine the information about the protection status and the user groups. With this solution we wouldn't introduce the "feature" of selectively hiding arbitrary content from certain users on any page. This class may be included only in [[MediaWiki:Common.css]], where we could define rules body.myclass (the element body isn't allowed in wikitext). We could also tweak the HTML code of the Wikidata links in a similar way, but that might be already exaggerated.