Right, you "shouldn't" need them.

Being an open, honest and upfront kinda guy, here's my story. I was swapping to a Gen V recently and pulled my motor apart. Found coolant on top of one plug and it was slowly seeping into the intake. Not enough to notice or make the engine run differently. When I tapped, I tapped that side a little far and the plug wasn't tight. I regooped the plugs to ensure they would seal and then being an L67 LIM with the recessed areas, I dimed them as well. Diming is when you bevel the edge of a dime with a file, rtv the recess area and tap the dime like a plug into the recess. Now I'm double protected. I did this work on the engine though. Most would have taken the LIM off to do it. In that case many other things could have been done, like some JB Weld etc.

If you did get a leak and you had the rings there..they should stop it from being a problem like I had.