The most recent news (a little over a month ago) was that the SL commuter trains between Stockholm and Uppsala would resume stopping at Arlanda at the earliest 9 October due to larger repairs than initially anticipated.
For a while there was only one operational track but I don't think that's the case because Arlanda Express is back to full schedule.

SL info, I only find a Swedish version.
https://sl.se/aktuellt/trafikforandr...ill-arlanda-c/