I went to BGG and I all got was this Overtext
If you lead with the +5 and no one plays a joker/wild rage or a trump you get it back.
I haven't had a chance to read the new rules, but I have been playing rage for years with my family. And I'm not sure how you meant it, but the only time you get the card back would be if you led with the bonus rage & everyone else laid a face/word card (not counting the wild). In this case you would win the hand and get the +5.
Someone else also said that it adds to the chaos of the game, which is accurate. In the rules I learned, if you were wrong on your bid, you got a -5 points. So, if you're already wrong and that bonus rage comes out, getting a hold of it can mean the difference between going back in points & staying the same (or even going forward a few). Hope that helps.