No. If it is a MM or EMH day with a regular opening of 8 AM, then the people with MM or EMH are allowed to begin entering the park at 7 AM or a few minutes before. Guests without MM or EMH are not allowed to enter at that time unless they have a reservation for Plaza Inn character breakfast at 7:10 AM. All other guests without MM or EMH are held outside the gates until at least 7:30 AM, more likely 7:45 AM, unless they have a Plaza Inn reservation for before 7:30 AM.
If the park has an opening time of 8 AM with no MM or EMH, then Disney opens the gates on an undisclosed schedule, possibly on some determination of expected crowds and available staffing. I have been there at times when the gates were opened at 7:30 AM, 7:45 AM, only a few minutes before 8 AM and some variations on this theme, but not before 7:30 AM (except in the case of crazy unusual circumstances such as the Star Wars Galaxy's Edge opening). Anyway, guests allowed in before the official 8 AM opening time on these mornings will be allowed most of the way down Main Street and then held at ropes at the hub. Restaurants will not yet be serving and usually the stores are still closed.
With later morning openings, adjust the times accordingly.