Sure, but even VS code has been pushing Copilot pretty hard and from the screenshots the setups look fairly similar. It's a recently released code editor with their own personal AI built in vs. VS Code which has the AI as an extension (or built in, I don't know what the default install is like these days).

If they're using it to auto complete lines of code or fill out boilerplate then I don't see the problem. If they're typing "make me a password manager" into the prompt window, hitting enter, and accepting it blindly, that's a problem. Also the code is (at least in this case) open source, so there should be better evidence of bad vibe coded code than the presence of a config file

I think there are better things to criticise Proton for, and unless there is more to the vibe coding than using the Cursor, citing this as a reason will get those other criticisms ignored in the noise.