[cimi_]

They probably mean new code not the entire codebase, but even so I think those numbers are ridiculous given my experience.

Is there any evidence of this (anywhere, not just MS or Google)?

[paulluuk]

I'm not sure if it's ridiculous if you factor in something like copilot. Heck, even just your IDE's built-in autocomplete (which only finishes the current variable name) can get close to being responsible for 20% of your code, with tools like copilot I think you can even more easily hit that target.