Incorrect. People in the Tron lines only makes other rides less crowded if total attendance is static, but it's not. If increased crowds > Tron capacity, net impact will be more crowding, not less.
Depends what kind of capacity we're talking about.
Let's take an example. Let's say a new ride can have 350 people in the queue and 150 people on the ride itself. And this ride's capacity in terms of People Per Hour is... doesn't matter. PPH doesn't matter if you want the park to be less crowded. If at any moment of the day there are 500 people in the ride (queue and vehicles), then it doesn't matter if those people are cycled through in one minute or one hour. The ride only takes 500 people 'off the street' at any one time.
To see this, let's take an extreme example: there are only 500 people in the park and they all want to ride this new ride over and over again. So, everyone in the park is on the ride. There are zero people 'in the streets'. Increasing the capacity of the ride in terms of PPH doesn't change the fact that there will still be no one on the streets. The increased PPH just means that everyone gets to ride the ride more often.
If there were, however, 10,500 people in the park. Then at any one time, there would be 10,000 in the streets and 500 people on the ride. As people get off the ride, some on the street enter the queue. And if they increase the speed of that exchange, it would still be 10,000 in the streets.
What this means is that a popular, or even just new, ride will almost always create significantly more crowding. Even if it's a new C Ticket. If that C Ticket can 'hold' 500 people at once, but 2,000 extra people show up during the day to experience the new ride, then that park will have an extra crowding of 1,500 people. Doesn't matter what the ride's PPH is.
Where increased PPH is needed is to give the people that do show up the ability to ride that ride and many others more often. Increased PPH means being able to ride more rides for each guest and enhance their experience. But increased PPH doesn't make the park less crowded.
Bigger queues, pre-shows, and vehicles that hold more people reduce crowding.
More rides that don't draw in more people than it holds at one time reduces crowding... but that's unlikely to happen.