There are 3 or 4 differences mechanically with the LE. It's contained in the huge Stern press release and on their site.
Artwork different as well.

Premium will feature diff cabinet art as usual and prob same LE Playfield features and its own translite.
Just look at all who have come before, like TWD or Star Trek or Mustang and you prob know what will follow next.
The Pro is always exceptional value for money and always feature packed.
JOhn Trudeau built Mustang. I believe he built WWE Wrestling. Mustang playfield and lighting on the Pro feels like a LE.
This WWE Pro lights up like the LE. Looks awesome already.
Le pitched to home and siting. Prob 80 percent to home.
Premium to home or siting. Prob half to each.
Pro to home or siting. Prob half to each.
That's what Stern usually tells me on most recent titles.