wordpress.org serves updates files when I release them… I really do not have anything to do with that and really have no control besides committing and tagging the update. wp.org even make the zip file, not me. That said, unfortunately, the only suggestion I can give is, try again. There’s already been almost 1100 updates completed so it must be working, hopefully this was just a glitch.
Not sure how much help my answer is, but I do hope it helps. Let me know.