Adding that text to the packaging guidelines seems like a sensible
idea, yep. You'd have to propose it in an FPC ticket, that's the
procedure for packaging guideline changes IIRC.
After discussing this on the packaging mailing list, it seems we don't need any
modifications of the packaging guidelines:
https://lists.fedoraproject.org/archives/list/packaging%40lists.fedorapro...
After further consideration, I've also created a FESCo ticket to officially approve
this:
https://fedorahosted.org/fesco/ticket/1534