Concerning "concerning"

Rereading Strunk and White, particularly the misused words and phrases, reminds me of something that's been bugging me lately:  the recent use of the word "concerning" to mean "worrisome."  I hear it a lot with teenagers.  "That's very concerning...."

My son used it, and I, being a mother, corrected him.  "That word doesn't have that usage.  It means, 'about,' or 'related to.'  It doesn't mean 'to be worried about.'"

But maybe I'm wrong.  I'm taking linguistics this quarter, and I'm discovering things about the language I never knew before.  For example, there's the bold linguistic statement, "No native speaker of a language can make a verbal mistake in that language.  It is not possible."  What that means is that however a person was brought up to speak is correct for that person, and no person should have her spoken grammar "corrected" after speaking.  However she spoke the language is correct, because she is a native speaker. 

Is your hair on fire yet?  Wait, before you explode, understand that the rules for writing are different and more codified than for speech.  All that means is that you'd better make your verbs and subjects agree (even though that's an arbitrary Latin rule imposed on the Germanic language in the 14th century) in your writing.  Don't worry about it in speech. 

So, what's to be done about "concerning"? The kids can't make mistakes in their native language.  That usage of that word is correct and carries meaning for them.  It separates them from me, yes, but that's what happens over time.  Youth and age are separate, and ever will be separate.  Time does that.  But what do we do about this word?  It's right for them.  It's wrong for me.  Is it their language now, and they form it, leaving me behind?  Is that what language does?  I know it's what time does.  Does language, also? 

Here's my problem.  The paradox is that the children coined new usage for this word out of ignorance of the old.  They saw the word "concerning," knew that "concern" had a particularly intimate connotation, and, not knowing the meaning of "concerning," applied what they knew about "concern" to it.  Now this is coinage from an error.  However, the children cannot make an error in their native language.  Thus they have coined a new, valid usage of the word. 

And yet, my mind rebels, and insists this is an error.  Am I wrong?  But I am a native speaker of English, and so I can't make mistakes in it, either.  What do we do about this? 

Here's what I foresee happening.  It will take a decade or two, but it will happen. 

Only some of these children will be "corrected" by teachers and professors.  Eventually, some of them will become teachers themselves.  They, using the word in this way, will not correct those who do.  (This word is proliferate on the internet in this usage.  It's really taken hold.)  In time, there will be more users than nonusers and the word will have the power similar to the split infinitive.  There will be holdouts stomping their feet and screaming, "It doesn't HAVE THAT USAGE!" but they, like most cranks, will be ignored.  And then it will appear in the dictionary with that usage.

(The dictionary thing may happen sooner than that, as dictionaries are descriptive, not prescriptive.  We think of them as rule delimiters, but what they really are is pattern describers.)

What do you think?