I'm flying United, and at time of booking I can select my seat.
On one flight the aircraft is designated as a 777-200. The seat selection diagram shows a 3-4-3 seat layout, ABC-DEFG-HJK. At time of writing there are plenty of seats so I've happily picked an aisle seat in column G. The weird thing is that for the entire length of the Economy section of the place the F column is not selectable. It's not marked occupied, just greyed out.
Question: what does this imply? Could the airline be considering using a different plane? Is there any possibility that my aisle seat could be resignated a non-aisle seat? Seems too good to be true that I've effectively picked a seat with no neighbour.