FWIW, I would no longer rely on the 10:00 a.m. Central timing as today proves.
For a while they did that, then they released earlier, then they went back to 10:00 a.m. and the last couple of times at least have been much earlier. They never have done a midnight release, but as previously noted the new fares were available for purchase by 5:45 a.m. Central today.