I think people are missing the big picture here. Universal doesn't really care about capacity within an area which is part of the reason for the open hub. The goal is to make as much money possible and people love eating out in well themed/design areas with good food/entertainment nearby. Additionally, those guests don't impact the data Universal likely is trying to collect in the long term.
The photo validation factor though is the real bread and butter. They don't need to use it like disney use Genie+ because Universal can use this technology to track every moment of your day in a way that magicbands can not.
Ex 1: Guest A enters the park in 4 minutes, he turns right for HTTYD, he enters line 1 for ride attraction at 0934, gets on the ride at 1000, ride breaks down for 20 minutes while Guest A is on it. Guest A manages to ride and get off ride at 1026. Guest A then goes to Mead Hall, in mead hall buys Product A, Product B, Product C for guest A1, A2, A3 who are with him. Guest A1 eats Product A etc... end of day guest A goes to Guest services to complain about ride breakdown and is validated by the photo validation time stamps. (mobile order somewhat helps with allowing Universal to get this data but it still doesn't allow them to see who ate what)
Lets go to the one I'm likely seeing Universal use this more lilkely for seeing as they are becoming way more restrictive on Guest Assistance Passes (GAP) and adding barriers to access due to the fact express is a massive benefit to speak of and each person misusing GAP is a group of people not paying 119 dollars per person.
Ex 2: Guest B has Attraction Assistance Pass for IBS allowing them to get a return time for an attraction via the paper slip. Guest B gets time for attraction 1 which is 75 minutes at 0900. Guest B gets a return time of 1000 to return and get in the expresss line. Guest B decides to get in line for attraction 2 with a wait time of 45 minutes and never leaves the line to use the bathroom. Guest B heads straight to attraction 1 immediately after getting off attraction 2. Universal staff members stops them and ask if they are following the procedures of the Attraction Assistance Pass properly.
While they will initially use this for turnstiles overall, the benefits of tracking each guest and the habits and how they operate in each restuarant, shop, path, etc will allow them to make strategic long term decisions based more so in fact rather than surveys which is generally anonymous and no fool proof way to validate truth. It allows for guests who don't use things like magic bands etc to still track their purchases, their behaviors, and their patterns. It also can be used to help prevent fraud with people lying to get certain benefits and theft of people abusing services. Overall this is a treasure trove of data.
That being said some people might see this as a negative. OMG this company has so much information about me. Facts they do have a lot of information about YOU but this also allows them to create and develop ideas that cater to YOU and people like YOU. If the tracking shows 86% of guests regularly go thrill ride to thrill ride, they will build thrill rides because the path and the data shows that despite surveys saying oh they want dark rides. If they see a bunch of guests move from a ride straight to a restroom, they may take it that the ride profile is causing illness despite not seeing the damage in the buildings.