My lay perspective is that it is apparently the other way around: It certainly appears that VS is increasingly "VS Code compatible". A lot of the extensions in the VS gallery have silently been working in more TS/JS code and even some of the "built-in" functionality relies on TS/JS code. (The Typescript compiler itself, of course, has always been self-hosted in VS. The DOM Explorer which can be used in webpage debugging and Cordova mobile remote debugging uses a bunch of Edge Dev Tools code much of which is also shared with VS Code as well. [Which is more reason the VS Code open source announcement is rather wild.])

It definitely would not surprise me if that's an intentional direction in VS and many more extensions and components will start to be built (or rewritten) for VS Code first as TS/JS and then "ported" to run in VS "proper". Of course, I certainly don't know anything of the matter for certain, this is just lay observation of trends I'm watching with interest in VS.