Originally Posted by
DaveReidUK
Although the Snopes article, as well as the quote from United in the OP's link, appears to confirm that they will be charging a higher fare for any passenger who wishes to bring a standard IATA-sized carry-on into the cabin.
Or, to look at another way, UA will be charging a lower fare for any passenger willing to travel with a small carry on that will fit under the seat in front.
In reality UA will board these ticket holders last. I doubt if any CC is going to argue if one wishes to use any remaining overhead space.
But it will speed up security and boarding and the pax can choose.