There are about 29 rides in the MK.
Let's just take into account the most popular 20 of them.
If there are 1,000 people an hour absorbed into show, but not any more, then they are in the lines for those 20 rides.
That's an extra 50 people per ride.
These rides have at the minimum and average of throughputting 1,000 people per hour. So, those extra 50 people are adding 3 minutes to each ride.
So even if one says that if shows were eating 3,000 people an hour, that's still adding less than 10 minutes per ride for lack of shows.