Read the article.
So here's the basic dilemma - we have a strong hand that isn't the nuts. When we consider betting the river, a general line for many players would be to check behind - our hand has strong sd value, but a weak A easily beats us, and is consistent with the way the hand has played out, depending on who the villain is.
If we bet, is he ever going to call w a worse hand, or is he ever going to fold a better hand? If yes, then we should bet/fold here (assuming you think a shove in this spot is never a bluff). If no, then there's no point in betting in this spot - if nothing worse calls, then when we have the best hand doesn't accomplish anything, and when we do have the worse hand, we lose the bet.
However, if you're up against thinking opponents, range merging can open up other opportunities in other hands, where you can get called by bluff catchers more often because you've shown that you're willing to bet w a medium strength hand.