It's not about genuine or not, it's how much that 2 boys sacrifice for her, knowingly or unknowingly. Okay that she's in love with Kaname and Zero, but at one point she's gonna admit that she loves one of them more than the other, even a tiny little bit. But she takes long time and with her hesitation makes the suffering longer. And I think between 2 males Zero is in more disadvantage and loss than Kaname. Kaname had a lot chance toward happiness, he just choose the hard path one. As Zero, his chance is so thin after his humanity was taken. At least Kaname has place to belongs, Zero is neither human, hunter, or vampire.
I think their relatioship is too complicated too put it in simple terms so I dont really regard it as polygamous as in those relashionships no matter how you try is impossible to love them equally But I felt here yuuki love them wholeheartdly and anywasys they needed each other
So Im happy with this kind of ending, whats more I was happy to see how in the end the three of them cared for each other plus Kaname hugging the kids i started tearing lol
some people hate that yuuki basically loved 2 guys. what's wrong with that? what's more with a polyamourous relationship? the involved parties were ok with it. so there's that. and she does genuinely love both of them you know