Hi Drew I think python3-scipy should declare a Breaks on python3-skbio less than the version in unstable (0.5.8-3). This should sort out the autopkgtest regressions of emperor, python-skbio itself, q2-metadata and q2-quality-control, which are all passing in unstable, and allow scipy and python-skbio to migrate together.
Python-cooler seems to have a different failure, and I don't see a bug filed for it. Regards Graham