https://www.cnet.com/news/nvidia-gtx-1660-ti-turing-card-spotted-possibly-for-feb-22-launch/

The naming scheme is potentially confusing, though. Nvidia's series names (for example, 900 series, 1000 series and 2000 series) have traditionally indicated the generation of architecture used in the GPU -- e.g. Pascal for the 1000 series and Turing for the 2000 series. 

It's understandable to have it bear the "GTX" branding since it lacks ray tracing, and "1660" does put it between the "10" models and the "20" models, but it's likely to cause confusion.