It'll be interesting to see how it does.
Assuming the interval between groups is 30 seconds, and the avg. group size is 2.5 guests, each house would have a 300 hourly capacity, or about 3K a night... so is 2-2.5K the capacity for the night? (Assuming Universal wants everyone to do all houses).
Back when the event's attendance was a fraction of today's crowds. Stay & Scream these last few years have been ridicously busy. Not saying it can't work, but HHN is a different monster today crowd-wise than in the past.