While I agree that it's legally murky in some respects, that seems like an opportunity (and a benefit to the writer of the OSS code) for a dialog between the maintainer and the user of AGPL code to ensure compliance.
Why would you want to open a bunch of loopholes for very specific and complex cases?
EUPL compatibility is not exactly "opening a bunch of loopholes". It's yielding to a very specific list of licenses, to very specific conditions that exclusively make the resulting license more strict (e.g. combining with AGPL basically turns it into an AGPL licensed work)
Why would you want to open a bunch of loopholes for very specific and complex cases?