Can’t confirm or otherwise, but it would be nice if KLM would adopt a consistent seat numbering system across its long haul fleet. Currently, the aisle-next-to-window seats are lettered as follows:

A330: B H
744 : B J
767 : B F
777 : C G
M11: B H
73W: B C

Rather confusing, to put it mildly.

A logical system could be based on ABC DEFG HJK, with A K always being window seats; C H always aisle seats on the window sides; D G always middle-block aisle seats; and B E F J being reserved for the middle seats, if any.

Johan