A series of interesting answers have been given in an interview by the executive vice president and chief financial officer of Nvidia, Colette Kress, the interview was performed by Seeking Alpha.
The interviewer asked about the improvements that the Turing architecture would offer for gamers and developers. In the answer to that question, Kress makes an interesting choice in wording in the sentence: "The cards will come out. We'll start with the ray-tracing cards. We have the 2080 Ti, the 2080 and the 2070 overall coming to market."
That answer specifically does not include lower-end model and could mean that (and it makes sense really) that cards like 2050 and 2060 won't be released for a while. Actually it is rumored that they likely do not get Raytracing cores, and actually might remain in the GTX line of naming. It could also mean it might take a while before cards like 2060 would hit the market.
In another sentence, Kress indicates that Nvidia will also be selling Pascal cards in addition to Turing cards. "We will be selling probably for the holiday season, both our Turing and our Pascal overall architecture." And here you read that the existing Pascal line of product will be around for a while, right next to the new RTX products, so that's at least leading into Q1 2019.