Well, it shows they're willing to address the issue of queue fishers. This is a subpar fix for a bad situation, but hopefully it means they're taking a measured look at this problem & plan to push back against it with other adjustments in the near future. Something like this should be in place for normal DF instances too. A flat 15 minute penalty for withdrawing sounds good, imo. There should also be a penalty for being dismissed from a group.