I’m not sure if it is WAI or a bug.
We have done level 10 Fractal (after the patch) with one of my character which could do level 11. He has 15 agony resistance. Before the patch i did not see any effect of the agony on that char at level 10 (or not in a way i could relly noticed). Now, after the patch i recognized, that the agony hit my char in a noticeable way. I did not chage any gear.