This is weird, on a number of different levels. Despite the fact that he created the Turtles, Kevin Eastman had signed away most of the rights to the characters. So including an ad for a product made from characters he no longer had an interest in would have been odd. Even stranger is the fact that this is for Nickelodeon and marketed to children. I guess there were probably some adults reading Heavy Metal who were heavily into collectibles (the ads over the years absolutely bears out this perception), but the brand crossover is just weird.

(Heavy Metal #269 2014 – Inside Front Cover Nickelodeon ad)