That would make sense... although it seems to me that there's far more to do at DisneySea than there is at DHS, that's got to help disperse the crowds a little better. Although nothing will help in the beginning, because everyone wants to ride the "new" ride anyway.
I seem to recall that when Monsters Inc first opened in Tokyo
Disneyland they opened the gates an hour early to on-site guests so they can ride it (and, weirdly, that was the only thing open for that first hour). I wonder if they'll do something similar in this case.