It's about time, GTX 1070/1080 will be over 2 years old by the time this launches. These will be the first consumer focused cards that will be able to take advantage of hardware based ray-tracing.
GDDR6 will reportedly power most, if not all, of NVIDIA’s upcoming graphics cards. This includes the upcoming gaming focused GeForce 11 series as well as upcoming Tesla and Quadro parts for the AI and autonomous driving markets.
SK Hynix has also confirmed to GamersNexus that GDDR6 will be entering production in three month’s time around late June, early July. This puts the the GeForce 11 series launch right around July, which happens to coincide with areport published earlier this month that put the launch also in the July timeframe.
I bet they'll save GDDR6 for the high end cards, when they moved to G5X they only put it in their most expensive cards.