This is why we can't have nice things. People push the limits as far as they can be pushed, and then it becomes standard, and then it becomes strategized for, and eventually WDW ends up feeling as though they have to take something away in order to operate the way they feel they need to.
Of course you CAN get into line up until they say you can't. I do think the question of SHOULD is reasonable to ask -- should one, knowing the published hours of an establishment, actively work to stay in the establishment beyond those published hours? I'm of the opinion that getting into a line knowing and planning that you'll be there beyond park hours is an abuse of a kindness WDW shows it's guest by not rushing them out. I'm part of a very small minority, I know, but I'm tossing it out just to let the opposite opinion be heard.