With alexithymia and interoception issues being common with autistic people, I'm not surprised there's some who conceptualize their speech difficulties or gradual complete loss of functional speech as "not wanting to talk", or even as a choice they're making, regardless of how truly voluntary it really is.
That indefinable "Don't want to talk" feeling is sometimes the first warning signs of not being ABLE to, at all, for some people: both in the acute sense of immediate verbal shutdowns, and the more long term sense of gradual partial or total loss of speech.
I think the dismissal of it ever possibly being serious is a problem. Obviously not everyone who cannot use speech has this experience, and nor does everyone who loses speech in some form, but it is one of many authentic experiences, however comparatively uncommon.
When someone, especially someone whose already had issues with communication or language, suddenly tells you they don't feel good when they talk, listen. Aside from autism, also, acute speech loss can be a sign of something that may be serious and needs to be addressed.
People can only use the words and language they already know to try and describe whats happening to them. For some that is getting very specific, learning the most technically-accurate terms and the latest scientific explanations for what's happening to them. For others, though, they won't have that knowledge or language for one reason or another. Some may not be able to fully understand whats happening to them without support of others or specific resources. Some may never be able to - but they know themselves, what they can and can't do, and need ways to communicate that to others not only for understanding, but also safety.
Drawing arbitrary lines and nitpicking the specific wording or terms people might use to describe their speech loss doesn't seem to be about helping people figure out what they need to communicate effectively, especially people who have a disability that can greatly effect language skills, communication, and the ability to assess internal states.
An understanding of what the "correct" words to use may never come for someone, but there will usually be a way to improve communication anyways. At that point, the people are the important part, not the words we label them with. Words are just a tool to try and convey a concept, to get something done, and you can't guarantee that a word will mean the same thing to every person who receives it.
And, if someone finds that giving up speech as primary communication is too difficult, they will naturally drift back towards it. If other communication is not more effective (or less painful, disgregulating, tiring, etc) than speech, then the path of least resistance will win out.
Being unable to rely on verbal speech is hard. It's scary. It's frustrating. It can often be dangerous in ways that most people would never even think about.
If someone "willingly" goes through the troubles associated with not being able to use speech, then how easy was speech for them to use in the first place?
How effective of a communication method could it have possibly been for them?
How long were they hiding and compensating for it before it became too much to bear?
How much a choice is there, really?
Does it really matter, at that point, whether they know if it was a "choice" or not?
