I think sometimes they might be call ego states or fragments.... perhaps centered around a particular emotion or trigger.

IDK how long you've been in therapy, but you know that not all your alters will fully identify themselves unless necessary I guess.... and being denied or ignored will send some to hiding. Can you "just" "allow" that THAT part of you has a job to do for you, and it's okay?

I think just about anything is possible with DID since it's the construct of the brain/mind and necessity. If you (it's all you, remember) "know" consciously or unconsciously that a particular aspect of "you" is no longer necessary I think that part will dissolve or connect with another part of you, or change purpose.... just like when we purposely wish to change some aspect of ourselves, we do it.

Hope this helped.