I used to work on Main Street East (Pandora, Uptown, Confectionery, Art of Cinema, Chapeau, etc) and this new theatre will completely change the way cast-members do things. Us castmembers really value that space behind the buildings to go out and sit on our breaks, there is also an employee cafeteria back there that I guess will shut down. I took my breaks back there quite a bit. A lot of people do not like to take their breaks in the cafeteria down in the tunnel.
One area back there is specifically for the balloon people where they fill up the balloons before they go out on Main Street, not sure how they will hide this when the new theatre is built. Security and PhotoPass also gather back there before/after they go out for their shifts.The coolers also sit out there filled with water where the stockers run to get water for the carts at the entrance of the park. The dumpsters for garbage are also back there so those will probably have to be relocated, it's where all the garbage and cardboard go from the confectionery, etc. They also have stock rooms for the confectionery and Starbucks that are back there.
I know that a lot of the leaders that work in this area do not take the West Clock bus and take the Pluto shuttle or park back in the parking area so I am sure they are not happy about this change and I am wondering if they will have to start taking West Clock and walk down the tunnel like the rest of us.
Overall though I think that big parking area was a waste of space and although some events do happen back there like (every summer they have the Employee Appreciation event in a tent in this parking lot, so that will have to be moved) I think a nice new big theatre will be a great addition. Plus I know alot of guests do not like being forced to walk down Main Street and it does get really congested (crowd control struggles to get people off the streets for parades etc) so redeveloping the back area as another walkway will greatly improve things overall. I am just saying that as someone who has worked in this area it's a huge game changer.