I'd actually worry if the engineers I work with couldn't pick up a new IDE/text editor, etc. pretty easily and quickly, if and when something like this happens. And I'd say the risk of it happening in the next three to five years is pretty minimal at this point.
Once you start making full use of your editor, switching to a new one and reaching the same level of proficiency takes a long time. I can edit code even in notepad, but I can't ever be as fluid in it as my main editor. I've changed my editor multiple times and it's a huge pain every time.
I doubt that switching an editor requires a disaster-recovery plan.
I guess they have lots of "solutions" to "design and implement".
the normalization of this behavior within the industry makes using emacs or vim even more satisfying.
it's nice to having an unchanging cement foundation to stand upon once-in-awhile.
They maintain a trademark on the name Visual Studio Code and some other bits. And it is maintained by a Microsoft team.
But the code itself is MIT licensed. You can build it yourself. I have. There are one or two forks of it out there.
https://news.ycombinator.com/item?id=9872976
https://thenextweb.com/news/microsofts-cross-platform-visual...
Contingency planning for this could be a small but wise time investment for dependent teams. VSCode could very well go the way of the Do... Docker.