Marvelling at the sudden fourfold increase of my high resolution matches, I noted from the T1a results tables that several of them had a variation from CRS of 309.1C that I did not share. My inquiry to FTDNA elicited the response that positions 309 and 315 are no longer considered statistically significant enough to exclude genealogical matches, and that the assignment of matches would no longer take them into consideration.
So previously I was under the impression that Bonnie Schrack's father was more closely related to me than Terry Barton and more than 200 others. But no more! Chances are now equal. Commiserations to all concerned. The FTDNA FAQ on mtDNA will presently be updated. I don't know if we are all still going to have a 50% chance of a relationship within 28 generations or not. (50% chance?). I would appreciate any comments.