there is a update on teh Leil Shishi Shmuess https://www.yiddish24.com/interviews/12/129736
from minute 22:55

That’s how I understood – the father went to the kiddush by himself

FC is not debunked. It’s not always properly used.
I know many families who have kids that use this method.
Another point I want to make is that the beginning of article needs to corrected.
A child isn’t born with autism…

And the more correct way of describing such a child is not “an autistic child” it’s “a child with autism” he is firstly and foremost a child. his autism is a secondary thing.

זיי זאָגן אַז די אָטיסטיק זיינען – ניט דער פשט אַז זיי האָבן מיט קיינעם קיין שייכות ניט; זיי האָבן מיט מענטשן קיין שייכות ניט, אָבער מיטן אויבערשטן איז זייער שייכות פּונקט ווי באַ אַנדערע, און נאָך מערער, ווייל זיי זיינען ניט פאַרנומען מיט מענטשן, נאָר זיי [זיינען] פאַרנומען מיטן אויבערשטן.

= They say that autistic [people] are – it doesn’t mean that they have no connection with anyone; they have no connection with people, but with Hashem their connection is exactly as it is by others, and even more, because they aren’t busy with people, rather they [are] busy with Hashem.

בפרטי

From the article–seems like the father is witnessing the typing as well:

Now, recalling this story, the father turned to his son and asked: “Were you perhaps Reb Zalman Leib Astulin?”

The boy immediately typed: “Yes, yes, yes.”

This does not sound like facilitated communication. It sounds like some kind of computer that “type“ by communicating with it. Facilitated communication, requires a person to move the hand of the autistic person.