What they did
Google addressed E-E-A-T in its guidance on creating helpful content, clarifying its status as a ranking input.
What they found
The doc says plainly that E-E-A-T itself isn't a specific ranking factor, while adding that a mix of factors identifying content with good E-E-A-T is useful. So Google treats E-E-A-T as a concept its systems approximate, not a single dial in the algorithm.
How much weight to give it
Official documentation, so it settles the common claim that there is an "E-E-A-T score". By Google's own account there isn't one.
What it doesn't prove
Saying it isn't a single factor doesn't mean the underlying signals are absent. Quality raters use E-E-A-T to judge results, and their judgements feed system training, so the gap between "not a factor" and "shapes ranking" is thin.