Unfortunately there's no news of threadripper for Zen 2 yet. Hopefully we'll hear something about it sometime next year. The assumption is they're using all their initial production capacity for consumer-grade (Ryzen) and server-grade (Epyc) chips first.

A new Threadripper has been confirmed for late 2019.

https://www.pcgamesn.com/amd/3rd-gen-ryzen-threadripper-2019...