It’s non-free, it’s non-libre, but it does pass the bar of open source software. The OSI, EFF, RMS or whoever don’t have to say it is in order for it to be true.
You can distribute it but there are limitations on it, you can make a fork of Grayjay that is free to use, review, re-distribute and add parts to it adhering to other open source licenses from whence they were developed as long as it’s non-commercial, and doesn’t make any representations on behalf of FUTO or Rossman, essentially.