A couple are Nasdaq but I posted them to show even NASDAQ companies can announce a ticker change prior to it being posted on a daily list.
Most companies release the PR the day the ticker change becomes effective, or the day before (when it hits the daily list) or one day after it becomes effective. This makes the most sense since the ticker change would have the most impact without a play by play.
Below are examples of companies that posted a PR prior to to it hitting the daily list.