In order for Samsung to maintain 18.5:9 ratio, if they widen the phone, the phone will get even taller. I hate to say it but they are going with the 18:9 trend and my guess is that they do not want to widen the phone any more because they feel that the width of it is the maximum comfortable width to hold in one hand. Since the Note is more thought of as a two handed phone, maybe they can widen it but they'll just have to make it longer as well to maintain that ratio, and I do believe that ratio is here to stay. This all has to do with maintaining that ratio and you just can't stretch it one way without stretching the other way as well.
I personally don't think it's misleading. To compensate for the corners, they are listing on the box that it is 6.1" vs 6.2" as as far as it being "longer" - no one seemed to claim LG was misleading with their G6. This is how they measure monitors - corner to corner. I guess now they need to consider mentioning ratio as well so that it is not confusing to people.
I am surprised, however, at how this has become a controversial topic. Many owners of the 6e, 7e, Note 7 have always experienced the feeling of the screen being smaller than was stated - mostly because of the curve and distortion that made the phones comfort viewing area to be smaller. Few people called it misleading though (however I admit that somewhere in these posts, I might has said that about the 7e and Note7 many moons ago).
I don't mind Samsung trying to innovate with LG rather than wait for something to become a standard after Apple decides it's the way to go.