1H 2017 is pretty much what was expected all along. That October rumor might be a dual Polaris card to bridge the 6 month gap.
Expecting to see before Vega 10:
450 with 2 GB GDDR5 - Next 3 months.
485 with GDDRX5 with improved Polaris 10 chips. - end of the year
490 with GDDRX5 as the Dual 480. - end of the year.
495 with HBM2 / 8Gigs only, and 4 months before Vega 10 AND if this gets delayed as expecting.