> Deno can run true TypeScript directly and not just strip types
What exactly do you mean by that? Because no js engine carries the ts types into the runtime as far as I know. Deno and nodejs both use v8 as the runtime. v8's internal types are not connected at all to the ts types regardless of the wrapper. The only difference might be when/if static type checking is performed.
I think they mean deno handles transpiling for you so there’s no visible machinery for this aspect of the program. It’s just convenient.