AGPL has language to cover such things, e.g.

> All other non-permissive additional terms are considered "further restrictions" within the meaning of section 10. If the Program as you received it, or any part of it, contains a notice stating that it is governed by this License along with a term that is a further restriction, you may remove that term.

So it seems at best there is a need for a middle man who gets the AGPL licensed version that can then propagate it further under pure AGPL.