From a CM perspective, this is a good thing. Fantasyland is the stroller parking capital of the world, we have positions at most rides called "stroller" parking and your whole job is to move strollers and keep them in order. The old strollers took up a lot of room and were quite bulky. They were much bigger than single and double personal strollers. The area around the stroller parking tends to bottle neck on busy days, this will cut down on the amount of room needed.
From what I observed, the old strollers had more room than they needed. Unless you are putting two large or two overweight children in them, it doesn't look like it should be a problem. But that is just by looking at the pictures. I can't comment on the single ones since I haven't seem them.
The biggest issue is that it was not uncommon to see kids up to 11 in strollers. Many kids that I saw being pushed around were old enough to walk. It seems the problem is that people let older children ride in strollers in the parks when they are too old for strollers at home. It seems like those are the families that will be the most affected by this.