>>10701961WWE held Summerslam in the old Wembley, they knocked that down and built an entirely new stadium with a different layout and capacity.
It's max capacity for seated concerts and events ranges between 75k and 90k depending on the layout of the set. They only do 90k for boxing and Rugby. You can't do 80k in Wembley anymore for a wrestling show.
1. space limitiation due to layout and
2. more stringent health and safety regulations since WWE was last there
and again, it's not the same stadium.