I notice people put their disorders in their bios on tiktok. iin?

I’m not on TikTok but I would never recommend advertising your mental illnesses or neurological disorders on social media, especially if you’re young. It’s essentially giving a potential predator a roadmap of what your weak spots are likely to be and how best to manipulate you.

Seems like a really weird thing to do. Imagine people putting "Queer, 25, Crohn's Disease/IBS"

First: tiktok is the most absolute useless stupid invention humankind could ever create! So what do you expect from people who use it?

I've seen people do that on Discord and a few other places as well, and the frequency with how often it's preceded by an LGBT identity, like you indirectly pointed out, is concerning.

Like, I'm not really concerned about you getting bullied as much as I'm concerned about your life in general. I've talked to people like this in real life and most of the conversation is dominated by their health/life issues until you've been around them long enough so that they no longer have to bring them up. It's a real downer. What's worse is that they have the easiest time connecting with other people that have similar issues, meaning almost nobody. I come away feeling fortunate but sad, and I really wish I could do something, ya know?

It turns into... this, I don't know, microcosm of medicated.

TikTok’s algorithm for what content they show you is incredibly hyperactive
You have to force your way out of seeing only the stuff you interact with, so you’re interacting with a lot of these folks type of stuff

If you don’t want to see what you’re seeing, you can ‘like’ certain ‘tags’ and you will see stuff that relates to that

Like I said on another similar post, unfortunately, mental disorders are becoming a huge part of (or even solely) people's identities now, which they shouldn't. It's also trendy at the moment to have/diagnose yourself with/fake a mental disorder (which it also shouldn't be).

If what you're saying is true, I think a lot of them use it as an identity.

Sometimes it's because they make content spreading awareness on said mental illness. Sometimes.
But from what I have seen with most people that put DID in their bio all they do is talk about their "alters" and "catch" switches on camera. Every video is just about them being a "system"...

Because many have now confused these things with an actual personality.

Autism and ADHD are not mental illness, they are neuro disabilities. One usually puts it in the bio to end stigma and to attract likeminded folks. The difference is that neuro disabilities cannot be cured whereas mental illness can even though its often hard.
BPD is a mental illness. You can cure a persons BPD with a certain type of specialized therapy. Ive never seen anyone put mental illnesses in their bio personally, such as BPD or depression or the like. I have seen people write about their struggles with mental illness in their posts though.