Yes, that is exactly what happens.
I compiled projects which are using pioarduino many times and the problem described in the first post happened a few days ago when I left VS Code opened for a long time - when I arrived back to the computer there was a message “Restart to update” and exactly the same happened to me.
Here I described everything in details the very same day when that happened.
I’ve been using PlatformIO since 2019. and have never installed pioarduino extension.