Personally, I don't think it will. There are 100 cabins, the majority of which have beds for 4-5 people. Even with every room at max capacity (which I can't see which allows for the rooms that have more than 4 people) that's only 400 additional people in Batuu even if they were all there at the same time. I really don't see 400ish people making any difference at all.
Also, reading the fine print, this is only 1 day of the voyage. If it works that all guests must arrive and depart the same day (similar to a cruise) then the guests from each voyage will only be in the park every 3rd day as the ticket is only valid on Day 2 of the voyage.