A couple of things Phil. Please check your stats for the word 'Distributed' rather than curated. Esther George has been saying for months how she would love to be curated and just this last week found out that she had been all along, 24 times! Medium do not send you an email any more about this, so it is worth a check. Re your various theories, especially the Editor one, well Esther George isn't an editor, so bang goes that idea. Likewise, I dont think that there is any mileage in your other theories. What I can tell you is that even my book chapters have been curated, which was totally unexpected. All I can say is just stick with it, it will happen for you as it did for me. Good luck.