As a point of reference, I have a late 2013 which does not qualify for the class action lawsuit extended warranty. I had the issue crop up at about 95k miles with a cylinder 2 misfire. Took to dealer, started with replacing spark plugs b/c they and Honda NA insisted my car wasn't covered. 5k miles later, cylinder 2 misfier happened again. This time, after researching on the board, I changed the offending plug (soaked in oil) and installed a muzzler. It has now been 17k miles, including a 600 mile road trip and a 1500 mile road trip, and the car has been great. No ECO mode and no oil. There was a little residual oil early on, but that has burned off.
I strongly recommend getting a muzzler. Just because Honda only covered 2011, 2012 and some 2013 models under their extended warranty doesn't mean that all those outside the range are free of those issues. Based on my reading here, many 2013+ vehicles still suffer from this issue. Better to invest $100-$130 now than to spend hundreds to thousands later for a preventable issue. Even a spark plug change is $200+.