Q: "Will the LCD and the EVF use the same interface?"
Would you prefer it if was or if it wasn't ?
Have it user selectable to show the same data or not. If the EVF and LCD can be plugged in at the same time, then maybe you'll want the LCD to show a picture without any additional data, while the EVF would show all the extra info like histograms and what-not. Or, maybe you want to see only the picture in the EVF and then the histogram in the LCD. Choices are always better than no choices.