I don't know about weaker, but I'm definitely seeing mechanics I've only ever seen in guides. Honestly, I kind of like it. I'm able to see all the mechanics I prepared for, and some of them can't be burned through like they used to be. On the other hand my alliance killed Phlegathon in Labyrinth of the Ancients before his second Ancient Flare went off, so I guess not everything has changed. Now that I think about it, the changes don't seem to have affected the ARR alliance raids at all.