Can other than natural phenomena be facts?
def. ideal of fact:
a thing that's consistent among all participants, i.e. a thing that appears intersubjectively "the same". And that has empirical/physical correspondence (i.e. verificationist, logical empiricist).
Note: this doesn't mean/require universality. This way e.g. a health claim can be factual, if it's factual in a group to which it is demonstrateable to apply. On the other hand it's not "universally" factual, because its factness is context-sensitive.
Physicalism. I.e. that all there exists is matter and it's measurable (if we know how). The better we can measure a claim against this physical, the more objective it's. "Actual physical" is the most factual context there exists and therefore it fulfills ideal of fact fully. But obviously not all interpretations fulfill it fully, so they cannot be fully factual.
The more interpretation between actual physical and [some interpretation], the less factual.
At the moment, I think that no.
The reason is that everything else than natural phenomena requires "interpretation" and everything else than "spontaneously created, emerged, ..." cannot be guaranteed to exist or have similar form (so that observers could observe similar phenomenon on successive times). Thus only natural phenomena can be consistently (time, place, observer -independently) observed and thus they're the only facts.
An interpretation of a natural phenomenon (by some observer, not necessarily the same for all) could be said to be "somewhat close to fact" or "factual" (meaning that it contains factuality, but is not necessarily fully fact). However, the interpretation contains the potential for "adding subjectivity" and thus interpretations about fact cannot anymore be consistently "as factual as the original fact".