Still waiting for the hammer to drop in terms of Alpha Chaos psyker. Kind of strange we didn't have an Alpha at all this turn.
It's not strange at all, if you look at the numbers we've actually gotten for the psykers we know of:
T110 - 0 Alphas, 11 Betas (6 Chaotic)
T109 - 0 Alphas, 17 Betas (8 Chaotic)
T108 - 0 Alphas, 19 Betas (10 Chaotic)
T107 - 2 Alphas, 17 Betas (9 Chaotic)
T106 - 0 Alphas, 11 Betas (6 Chaotic)
T105/104 - 2 Alphas (2 Chaotic), 13 Betas (8 Chaotic)
T103 - 0 Alphas, 11 Betas (6 Chaotic)
T102 - 1 Alpha, 8 Betas (4 Chaotic)
T101* - 0 Alphas, 1 Beta (1 Chaotic)
T100 - 2 Alphas (2 Chaotic), 8 (4 Chaotic)
T99 - 0 Alphas, 9 Betas (5 Chaotic)
T98 - 0 Alphas, 9 Betas (5 Chaotic)
T97 - 0 Alphas, 12 Betas (6 Chaotic)
T96 - 0 Alphas, 12 Betas (6 Chaotic)
T95 - 0 Alphas, 9 Betas (5 Chaotic)
T94 - 1 Alpha, 9 Betas (2 Chaotic)
T93 - 0 Alphas, 11 Betas (7 Chaotic)
T92 - 0 Alphas, 6 Betas (1 Chaotic)
T91 - 1 Alpha (1 Chaotic), 6 Betas (3 Chaotic)
T90 - 1 Alpha (1 Chaotic), 6 Betas (2 Chaotic)
T89 - 0 Alphas, 6 Betas (3 Chaotic)
T88 - 1 Alpha (1 Chaotic), 4 Betas (4 Chaotic)
*After Green Awakening, psykers killed off in droves
By the numbers, we had 11 Alphas total over 22 five year turns since the warp rifts started opening. Only 7 of those were Chaotic. So not really unusual at all that none showed up. Betas on the other hand are more common, and appear to be getting more common.