AFAIK they were not weather nerds / atmospheric scientists, and did not work with researchers on the use of the data, or do any work on statistical verification to know if their barometer data was helping or not, so I expect that they just collected some data but didn't use it.
But Apple could be in a prime position to use the barometers to make weather forecast accuracy improvements.
Google too, of course, but AFAIK they are not working on this.