Those were known factors. I'm referencing Powell, in the late December meeting. There wasn't much substantive change in terms of knowledge about how much build

Those were known factors. I'm referencing Powell, in the late December meeting. There wasn't much substantive change in terms of knowledge about how much building was going on since the prior September GDP release that would say "yes, after September we learned X, so that's why forecasts were lower than actual". In his address, and in his followup with questions from the press, Powell specifically talks about data centers and AI-driven productivity separately. These aren't context free data points you have to interpret, this is synthesized analysis being delivered in a report by the Fed Chair, giving his & the reserve's own interpretation. He could be wrong, but it is clear their belief is that AI is a likely factor, while also there is not certainty on that interpretation. They've up'ed their estimates for April though, and this advanced estimate from December is about to be followed up with the revised, final numbers on Jan 23'rd, so we'll find out a little more then, and a lot more in April.