I think early March, mid March at the latest, would be the best because the season is winding down and tryouts are on the horizon. Cheer in many gyms is a year round sport so you can't wait until the season is over to release information for the next season, it needs to be done before the season is over.
Here is something that I find tricky though. I know that the seasons are different for the international teams and they often times get the bid for worlds almost a year before worlds comes around, but can't that become a conflict with the release of information? The age for the international division hasn't "offically" changed yet but we know it will, since that age is different then those teams that have already won bids for the 2013 worlds will possibly have won it while having an underage athlete on the mat. This isn't their fault at all because they couldn't control the rule change, but it seems like it can be a conflict for them as to replacing those athletes now.