I think I know what you mean and it sounds naff because they finish the song when the crowd is doing the vocals as if the song was going to continue round another time. The fact is the last vocal of "livin' on a prayer'" doesn't fit over the outro they've stuck with on all live versions prior to the most recent ones. Jon dropping an octave and doing the "Woah, oh oh"s amps the song down gently as opposed to all in one go which is why it kills it.