[dang]

I don't see any inconsistency. Users are asked to submit the original source as the top link. Workaround/archive URLs are welcome in the comments. We sometimes put such links in the toptext too. It works the same for any site.

[nailer]

There doesn’t seem to be a good reason to not apply the submission policy to the top text, for the same reason it’s applied to the link.

[dang]

The toptext is often used for archive links which allow users to read otherwise-paywalled articles.