Well, we'll just have to rely on our experience then. I haven't dealt with dedicated servers plans, but my impression of "DDoS" protection in that regard is that your traffic will get blackholed if it's bad enough.

Vendors like Cloudflare, Akamai and Prolexic sell plans where all your traffic is routed through their networks first, filtered based on various DDoS-detecting algorithms, then sent to you. $$$$

You can't exactly route real-time game traffic over proxy designed to filter http traffic.