6Н23П-EB (6n23p-ev) IS 6922. That's exactly the case for ElectroHarmonix (EH) branded tubes sold as 6922. A 100% electrical equivalence exists.
How much sonic difference will be present, if any, in a buffer (cathode follower), when the tube is "rolled" is, indeed, a question. Good NOS 6922s are damned expensive. The best sounding current production variant is the "reissue" Genelex E88CC, but that variant carries a 45 USD price tag. FWIW, I say use the tough Russian tube, as it has decent sonics and it will last.