What is AI-taint and why is regular vim tainted?

I would guess it means they accepted AI generated submissions into the vim codebase.

There's a discussion in the EVi repo about needing to find people who know vimscript. Funny enough, I am planning to use contributing some vimscript to an extension as my first AI coding agent project partly because I don't know vimscript well. Although that does mean it'll be hard to critically evaluate the output. I can compare it to the rest of the code in the extension at least to make sure it fits the style.