It’s no problem whatsoever. And please believe me, there is NO SUCH THING as someone being scheduled for a specific bus on the way from airport to resort. From resort to airport you ARE assigned a specific bus pick-up time … but when you land in Orlando, you are NOT assigned to a specific bus or time ahead of time … no such thing.
So the short answer is that you could land at MCO at 10 a.m. and go to the DME area to catch a bus at 8 p.m. and you’ll be accommodated. They won’t even know that you landed 10 hours earlier! No one will know and no one will care.
Anyone who has specific DME questions (but doesn’t want to ask them here) is strongly advised to call DME directly at 866-599-0951. The cast members who answer those phones are DME cast members, and they will be able to give you exact answers even to your very complex questions.
But if you call the main Disney number (or any so-called “direct” resort number) you’ll be speaking with a call center cast member who has no specific training in DME. They are famous for giving laughably wrong answers to anything outside of their area of training, which is limited to resort reservations, dining reservations and ticket sales.They are NOT experts in details about the resorts, the restaurants or the theme parks.