Actually, under 10, since the first beta, you must make contact with the banner notification itself and then swipe up. Prior to 10, this was unnecessary, and a quick flick up from outside the notification toward the top of the screen would dismiss. I appreciate an instruction guide for dismissal, but it is unnecessary, and doesn't respond to my point. I know how to dismiss.
I haven't noticed, always assumed you had to make contact with the thing you're swiping away which kind of makes sense. You point was that notifications are now more difficult to dismiss which I have noticed. If your point is based on having to make contact with the item you are dismissing it's quite weak. Is there something else they've changed that you're referring to and I have noticed in the betas?