devtrackers.gg
After dusting off my chrono tank and going to vg they are definitely aggroing on illusions/avengers at least. I had an avenger up, bugged and stuck on wall it was was very easy to see it take aggro and boss run over. When tanking at the pillar any phantasm caught on the other side of the pillar also caught the bosses aggro causing him to walk out of the arena and despawn in an effort to get around the pillar and attack. We then tanked on druid and had no aggro/pathing issues at all.
Interesting. Thanks!