I've never eaten there, but when we went to Epcot for our early Segway tour last Sept. there were folks heading in for early ADR's there (around 8am or so).
WS is roped off for the most part that early. They specifically direct you where you can/not go. So if you are looking to get a jump on the F&W activities in WS it really won't buy you much. They won't drop the ropes & let things start until 11am.