I wouldn't be surprised if he actually has something for 9.3+ but I also don't think that edit means anything. However the kernel exploits on 5.0+ were known of for a long time but never mentioned on 3dbrew until Gateway released their update so it wouldn't be the first time the elitists are intentionally holding back information so as to not give people any clues.
Any dev who finds something, I'm pretty sure, will always hold there trump cards










