No, but that doesn't necessarily make the trend some kind of plot to change racial attitudes.
More likely, these ads are exploiting preexisting racial attitudes to make them more eye-catching. We take notice when we see a mixed race couple on tv because they are so rare in the real world. For a lot of people, seeing an attractive mixed race couple will provoke at least mild curiosity, and at most an intense excitement. It provokes a sexual response, either positive ("oooh, how exotic!") or negative ("they're taking our women!"). Best of all it's something controversial, but also something that no one can complain about without being suspected of bigotry. The mixed race ads stick in the minds of a lot of potential customers, and that may be enough for some of the advertising agency's clients.
Of course, even if it was some kind of intentional plot it seems pretty harmless. Isn't a world where race doesn't matter more preferable to our own?
ads are supposed to be about selling products
you will have a hard time convincing me these ads are not designed by like minded Genx and Y urbanites and social engineers