I think a couple of things for Disney's decision to keep the first 3 days non EMH and no advantage to on site guests
1. They are expecting most of the true SW fans to go to DL
2. We have 34 resorts here, providing EMH for those first 3 days would increase the lines exponentially at 9am for non resort guests
3. Giving everyone a level guest experience, allowing the SW fans that couldn't make it to DL the opportunity to be here for opening day and experiencing it on a level field
4. Getting the SW fans to experience the land for 3 days end then providing a better guest experience for resort guests for their EMH. Hard SW will want to be here on opening day, they will get their experience (3 days worth if needed) and then they will leave the park for resort guests to enjoy on their EEMH
These are just guesses, I was obviously not in any meeting. From a local POV I think it's great, I will be there bright and early (midnight) to line up with all other SW fans and experience opening day as a community.
I did have a resort reservation for opening day but seeing as it is not an advantage I was able to move it to Sept. for EEMH I plan to be there, the latest by 3am