I agree.
It might not come out later because it isn't the same anymore though.
Basically! People grow and change. I don't know what age the brain stops growing, but it doesn't stop the functions from growing. I think circumstances can change a person (ie, traumatic events, upsetting events), but that's not necessarily related to type, because issues (mental, physical, or whatever) don't exist solely because of MBTI. Some people are born sick, some people develop illnesses (threatening and non-threatening), or PTSD or depression or anxiety... and all of that has nothing to do with type. An extrovert can get cancer or be depressed or anxious, just like someone whom is more introverted can. They can be a 4 or a 9 or a 1 or a 2 on the enneagram.
I'm kind of generalizing here, and being overdramatic. But repeating myself/echoing your point, that the types can change because we grow and change and go through life things. And sometimes that expands our cognitive functions and we develop them more. And before, they were under-developed, because maybe before we were a kid, or a teen, and mistyped ourselves, or something. But sometimes when a person meets like-minded individuals, they realize they're a different type. Or sometimes it's with soul-searching or something; you know, realizing stuff.
I mean, it's not that deep, but I'm just saying.