When looking across a single companies codebase, how will you distinguish "best practices" from "we know this is bad but it works don't break it"? I have yet to work somewhere where the former is more than 5-10% of the code in production so I worry about this making it harder to raise the bar.
I would find it a more compelling pitch to say tabnine will help me and my teammates follow more general best practices, though I understand how subjective that is.