I think one can both learn about the new features without feeling the need to use them all or refactor old code.
My biggest learning while writing this was just how much is possible in JavaScript and TypeScript now, but I also realize that a lot of this I will not use myself or only use to understand some really specific code.
I haven't found one yet, but I'm sure there's one somewhere out there. I will try to keep updating this article so someday it will be what you're looking for.