Nah, I actually met the couple in person once and they confirmed. I didn't even know what to say.
Back on topic: at least he's honest about his "mostly anything" diet.
As amusing at that is, it is just a factor of the multiple choice nature of the question on OKCupid. You can say your diet is "anything", "vegetarian", "vegan", "kosher", or "halal" and then qualify it with "strictly" or "mostly"if you want.
So he had to put "anything". "Mostly" is a bit odd, you can leave the qualifier blank, and they are more applicable to the other options. But "Strictly anything" and "Mostly anything" are both really common answers on OKCupid, so it is hard mock Chris for it.
If you really want to mock him, I would suggest that most people answer "Mostly anything" because
a) They want to imply they are not a picky eater and they like a variety/trying new foods
b) They want to suggest they are open to/don't have a problem with other diets.
c) They think it is an amusing wording based on a small "glitch" in the choices, and say it as a joke other okcupid users would understand.
I doubt any of these apply to Chris. His completionist to filling out his profile just drove him to fill in a qualifier, even when one didn't make sense.