For anyone else wondering like I was... The T14 will be the replacement for the T490 and T495. Likewise there will be a T14s to replace the T490s and T495s and a T15 to replace the T590. They will no longer distinguish between Intel and AMD in the model name.
There's a Thinkpad E495 (previous-gen Ryzen/Vega) review on notebookcheck. The "E" series (fka "Edge") is a budget notebook though; for example, it uses slower memory and doesnt't have keyboard lighting/fingerprint sensors. I can confirm an E495 works perfectly with Ubuntu 19.10 OOTB; not sure the newer Ryzen is already fully supported by Ubuntu 20.04 LTS coming out these days.
There is a T495 review on notebookcheck, but it's based on previous gen CPU and it lacks Linux coverage. Possibly the Ryzen 4000 model will be called T14/T14s instead of T495? No review of those either though.
