They aren't actual server crashes. It's just an attack on the wires on the way to the server, disconnecting the majority of players. But yes, I've had a failed Pilgrim's run due to it and a near-failure that someone anticipated and saved. Everyone was kicked when I entered Unreal this week. I've had a few hunt trains ruined by the DDoS, and others delayed by 20 minutes where we all waited for eachother to reconnect before killing the rest of the hunts.