While I do agree with the sentiment that this post was a bit harsh, someone's kid coming out is definitely not ambigous loss, and I'd assume it's real insensitive to anyone struggling with that to imply the two are the same.

The below is from the Wikipedia page on ambiguous loss (so I'm not sure if this is 100% accurate, I'm not an expect). Ambiguous loss is defined as, "a loss that occurs without closure or clear understanding."

The first type, physical loss, is when someone's body is not around physically (e.g. missing person cases) but there's still somehow a chance they might come back, which leads to the absence of closure that defines ambiguous loss.

The other kind is physiological loss, in cases where a person's body is still there but they're not the same anymore (e.g. dementia cases). The fact that the person you know is simply not themselves, but their body is still living and breathing, is what leads to the absence of closure in this scenario.

Of course, this information all came from the Wikipedia page on ambiguous loss, so if there's definitely a possibility I'm wrong in one way or another. Very sorry if you are an expert or otherwise knowledgeable in this field and the information I found was unhelpful or misinformation of some sort.