I think Nvidia could have done great things with a 1680/1670. If they performed like their ray traced alternatives at lower power and were $100-150 less, Turing wouldn't be such a failed line anymore. It would kill their RTX line though.
From what I have seen of the RTX 2060 and 1660ti the new cores perform a bit better than their old 10x0's. That said not enough for a 1024 core 1650 to pass the old 1060 3GB 1152 cores. Now the old 1060 3GB kind of vanished because it was being out classed by a much cheaper RX 570 for $169. Point is I dont expect the 1650 to sale for much better than the old 1050ti launch price of $139. It may match the RX570's current price of around $149 if its performance is an equal.