Yeah, that technically is dismissive, and openly dishonest.
If you want to call it a disorder, then you should be willing to admit proper treatment is transitioning into a body and or gender role that is more comfortable to the person experiencing the dysphoria.

While it would also be wrong to deny treatment or general respect to anyone based on those above mental illnesses, it's also not the same thing to call gender dysphoria a mental illness.

This whole thread was spawned from a comment saying "If you have any compassion for people who suffer from transgenderism or Gender Dysphoria, you should not promote this illness as a lifestyle choice." and the post that comment was on is literally about transgender people being mistreated by the general public, with an example of someone actually dying.
To follow that up with a claim that the post shouldn't be made because it "Supports and illness as a lifestyle choice" is clearly making a statement against supporting the needs of people who are trans-gender.

There is good reasons why it has become outdated to consider Gender Dysphoria as a mental illness, again it is akin to the outdated concept of labeling homosexuality as a mental illness, or left handedness...
As for connections to suicide, dysphoria with any serious part of life alone could explain that, and then on top of that you have the extremely hostile attitudes that come from various parts of society, and it's pretty understandable why transgender and other LGBTQ groups often have high suicide rates.
The problem there should be clear, that one of the biggest problems with gender dysphoria isn't just the dysphoria, but dealing with trans-phobia.