I don’t remember “TS runtime” as you’re meaning it ever being pitched. I don’t think Ryan would consider that in scope for Deno unless MS wanted to collaborate on it.
This is the marketing line on the front page of the Deno project:
> A secure runtime for JavaScript and TypeScript.
They are using the same term "runtime" to describe JS as well as TS. All replies here by Deno team members use the language "Typescript support" but nobody here is saying TypeScript runtime.