PLEASE THINK CRITICALLY:
They're not going to waltz in there and speak off-the-cuff. You can be damn sure their message is going to be carefully premeditated and crafted by a team of PR executives. Do NOT let yourself get trapped with their gaslighting and spinning of the situation. Don't drink the Red Bull-infused koolaid they're going to try to sell you.
At the same time, do NOT come off as some drunk idiot ranting. Be very clear in your message, and be very critical and unforgiving. But save the, "fuck you Curtis you fucker" and such to the message boards. Nobody's going to take you seriously if you sound like a rambling child throwing a tantrum. Make it clear that what they did is utterly embarrassing and irreparably unforgiving. But say so in a way that they have no choice but to take the message seriously.
This x1,000. My line of work takes me to a not insignificant number of these kinds of events. Some pointers...
1) Don't get emotional. I know this is an emotional issue, but it needs to be made clear this is about more than a coach. This is about 17 years in the wilderness, with a constant churn of personnel and no real direction before Petke literally fell into their laps and gave the team a personality and a direction. There's going to be 300 people there. You can't guarantee all of them are going to be as pissed as you are. Once you start getting emotional, rather than rational, you seem like a lunatic and lose support. One of two of these types and your cause is torpedoed.
2) Kind of related to #1: Don't yell. The best way to get your point across is to be blunt. You might think raising your voice is some kind of theatrical flourish, but it's not.
3) Stay on message. Once it becomes about "and then and then and then" you lose people. We're pissed because, after 17 years of futility, we had in place a coach (who just happened to be a fan favorite) who built a team we could be proud of, who was unceremoniously fired for no reason.
4) You're going to have three minutes max to speak. Probably more like two. Maybe less if they want to be particularly underhanded. Keep it short and pointed. If you can't get a direct, pointed question out in two minutes, don't speak, don't go and give your spot to someone else, as hard as that may be. Nobody's here to listen to your five minute rant. We want answers and accountability. Make them face the music.
Basically, rationality > emotion and keep it short.
Take these for what they're worth, but I've seen plenty of people with legitimate questions and concerns dismissed because they come off as lunatic windbags. The last thing you want is to give Curtis the satisfaction of driving home with the impression his critics are crazy people.