The “lost language” canard was simply a reason to justify the father’s spouting of Islamic crap!
Absolutely nothing more than that and the canard may have been worked out with the Muslim brotherhood staffers that Obama has installed in his White House staff.
So your theory is that the father used that to boast of his language skills? I find that fascinating! That plays into my instant take that he was the biggest narcissist since Cindy Sheehan.