I had the same thought. As far as changes go, this one is a pretty minor inconvenience to runners and less likely to get the same backlash at the Tink experiment. And there will be people like me who actually prefer the earlier start.
My main concern for disneyland half would be what if this time change is not the only experiment. What if they have others or are trying to couple this early start time with less to no characters on the course. Also, I don't think the selfie stations were to accommodate people that cannot get in line because they cannot keep pace. I am starting to think its because they want to get these people off the course faster and selfie stations take less time than character stops. I would hate to see less to no character stops and more selfie stations as part of this experiment.