If Discord says they delete the PII they collect and they ultimately fail to do that, whether by malice or negligence Discord owns 100% of the blame.
If I get drunk and drive the wrong way down the highway and cause a wreck, the blame is not shared because the victim was driving a vehicle which is known to be a risky activity. I am culpable, full stop.
I hope we agree that there's a spectrum, and sometimes the victim is the one at fault. We just have to disagree about this specific case. I'm OK with that. All the best.