I think you are correct, but there are nuances. The one assumption you've made that peter11435 would (I assume) argue against is the 1,000 guest number. Where I would argue the gap lies is in Park Capacity vs. Attraction Demand. The hours in the park and park capacity (i.e. how many people they actually let in that day) is the most important. However, it also assumes you have a proper balance of your attraction demand. This is why MK - and at one time Epcot - was easier to control.
The current example would be Boo Bash. You have park capacity (number of guests) and time (hours) that forces choice. MK has enough attractions perceived as in demand where people will have plenty to do. In this case, they added "attractions" (i.e. candy and cavalcades), which reduces wait times. Your example works here. Other than the price, guest satisfaction is probably pretty high here. People have options, are filling their time and any perceived "missing out" is simply because I didn't have enough time to do everything I wanted.
Let's try a different scenario. Let's do Boo Bash at Hollywood Studios where Rise (and all attractions) are just on a normal standby queue system without FP/Genie. I bet you would see a VERY different experience. Assuming the same number of guests, you would likely have 75-80% of guests queueing for Rise. Some people could wait the entire 3 hours and still not make it on. Adding more attractions here may have some minor impact on Rise - but its big impact is on guest satisfaction. The people who got on Rise first will have an amazing day - as the other attractions will have virtually no line. Others farther back will have a horrible experience (effectively only riding Rise or nothing at all). The demand is out of whack. You would need a legitimate competitor to Rise to make a major change in the wait times/number of attractions.
(The same idea also plays out at parks. MK is the "must do" for most guests. So the demand/capacity/offering calculation needs to be different there than DAK. Or, you have to focus on DAK to make it a legitimate MK competitor.)
Bottom line - adding one attraction does not equate to adding a different attraction. And, the park, capacity (actual or artificially imposed) and demand all have to play into the equation.