I read a few dozen comments to see if I could get an answer to this in the thread, but it does appear to be a case where we're highlighting one of the risks of picking up a new license: folks don't agree on how to interpret it.

I'm very curious why the author didn't simply use AGPL, but I haven't done a deep dive on the text of the EUPL, so maybe that's the next step.

EDIT: Went to go research this. First thing I learned is the license has been around since 2007. It was updated in 2017. So maybe scratch my comment about it being a new license!