Building the open source repo gets you something which isn't VSCode. It doesn't install a lot of VSCode extensions, therefore you shouldn't call it VSCode and shouldn't say VSCode is FOSS.
This is very well put. If the open source repo was named "VSCodium" it would communicate better what is going on. (Chrome / Chromium.)
Edit: to be clear, I think Microsoft should offer VSCodium themselves and state clearly that they take that, bundle it with other stuff, and are calling that blob VSCode.
