I'm not sure I know what this pattern has to do with Bach, imitative counterpoint, or equal-temperament, but it is lovely all the same. It should be mentioned (probably first and foremost) that Rosalyn Tureck's performance on this LP is fascinating and worth a listen. Two interesting Tureck factoids: she was Glenn Gould's only cited influence, and, even more interestingly:
made her Carnegie Hall debut on the theramin!