WWE has recently been referring to the Elimination Chamber structure as "all-new" which has had some people confused. This week on Wrestling Observer Live Bryan Alvarez noted there have been some changes made to the structure.
The reason we have not seen an Elimination Chamber match in a while is because many modern arenas have upgraded their set-up to having a large scoreboard hanging from the roof which has made the logistics of hanging the structure difficult. The structure is said to weigh in the region of 10-tons, so one might imagine the changes that have been made were to reduced the weight.
We'll be sure to update you on these changes when the structure is revealed on Sunday!