She was made up. There's no way to tell if she was made JUST to sell an action figure. That's just something you're assuming. But, I don't think it's a bad assumption. Either way, she's a pretty demanded character so if it was all some ploy on Mattel's part to get people excited about getting new action figures made (which would not be all that surprising since... well.... there's a pretty long tradition of that in MOTU
) then it worked.
I, personally, just found the idea funny that it was somehow a negative because
making up characters to sell toys is what Mattel does! Some of them I could do with out (Skeleteen... assuming he does get made at some point) but some I'm happy about (Despara, Dare) but either way I don't begrudge any their existence. From 2015 on, pretty much anything we get is gravvy to me.