Looking at it, there's more space than I oringally thought. There is a sizable building behind the Cafe - it's got the same theming as the Tower - assuming this is nothing to do with that attraction, they can expand into that area easily.
As for Studios Blvd., if it does take a straight path from where the Tram Tour station is, there's still plenty of room to expand Studio 7. I'd guess it could go as far as where the prop cars in the Tram Tour are now. That'd also be a logical place to have a second entrance into Marvel Backlot.