Some people seem to like building up an Array, by starting with an empty list and calling concat() with extra items.

A trivial minimal reproduction would look like this:

const a = [].concat([1]).concat([2]);

When you apply the autofix, it comes out like this, which is clearly nonsense.

const a = [[1]].flat().concat([2])

It seems the intent of the rule is to stop me using some arcane technique to flatten arrays, but the developers intent here is just to build up a flat list of entries rather than to flatten an Array