I think the key word is “We” are required. In other words we Catholics have a grace and a burden. The magisterium says There is a Purgatory? Then it must be true and we Catholics do not have the luxury of not believing in it. However, Those “who through no fault of their own are born into such eclesiastical communities”, I believe, it is not held against them. I believe the same is true about the Marion dogmas.
I believe, and will defend, every Marion dogma. But Mary is not the way to heaven. She can point you in the right direction, and is a huge help to those who emplore her though. And she knows the way better then anyone. But she is not the way