Ryan Ding of Huawei is waiting for updated Broadcom firmware, which he expects before the end of the year. He will then be able to supply units for telco trials "in the first half of 2018."
Ding and everyone else are working diligently to get the DSLAMs ready to deploy in volume as soon as possible, I think late 2018 looks most likely. We won't know for sure until we have several months of tests.
Preliminary reports are that both the Sckipio and Broadcom chips are reaching 1.5 gig.