Stumbled on someone decrying TikTok "multiplicity kids" on twitter, but not sure how I feel about this thing and there's no wikipedia article which is usually the limit of my research.
On one hand DID and OSDD are real things, though some people say it's a culture specific disorder.
On the other kids having calling themselves "we", claiming to be piloted by Harry Potter characters, real-life serial killer and Minecraft YouTubers seems to silly to not be just good clean fun.
On the third hand is you told someone thirty years ago about gender spectrum, genderfluidity, xenogenders, bi lesbians, autism spectrum, they'll probably think you're insane. Maybe there is a subclinical version of DID, like Asperger's to autism, so to speak? I dunno...
One is a bit less dark. Also the stillborn sibling thing seems like it could be a bi-product of parental behavior regarding such a loss. Minecraft YouTuber imaginary friends is a little more innocent and less likely to be harmful/the result of something harmful