Come on, nobody is preventing anyone from running the binary with strace or with wireshark open and comparing it to a version compiled from their sources. It's absolutely something which would've been relevant in a post like this one.
None of that would fall under ‘reverse engineering’ in this context since those techniques are basic due diligence that would be required before running software from a disreputable source like Microsoft.
Simple: you don't accept a license. If you want to reverse engineer it, just do it. You don't need their permission.
You can download the .deb/.rpm without accepting the license.
I strongly agree, as I said in the article by license using VSC your renounce your rights to reverse-engineer the VSC. So you take a legal risk making it and blogging/talking/podcasting about it on Internet and can face legal actions.
I’m certain the community would be very surprised if Nadella’s “OSS is good” Microsoft tried to go after an independent research post citing that clause. It’s there so they have some legally valid substance to roll with if they want to go after a significant case. Say, Jetbrains implementing something that blatantly seems to have been inspired by reverse engineering a proprietary part of VSCode. Not a good example and VSCode’s proprietary bits are so minor it probably isn’t worth pursuing but it should highlight the difference. Keep in mind too it could gain more proprietary features in future, added without needing to update the EULA and bothering users with Yet Another Policy Update they have to agree to.
Reverseenigneering might be forbidden in the united states. In many other countries however it isn't, especially for those cases, where you aren't trying to steal a product but to learn/research something about it