Thats the argument. If Oda wanted to complete or at least "start" the Enma hurting Kaido plotline, he'd have to have Zoro fight Kaido anyway. It doesn't mean it has to be his full blown fight, just that the clash needed to happen and potentially Wano ends with Zoro pulling a Ryuuma on the Yonko after Luffy wins or something.
Any number of factors can make King/Queen involved with Zoro and Sanji, we just have to wait and see. Some fanboys can't even see the possibility because they have their horse blinders on too tight, but everyone should be open to any possibility because its extremely possible the rooftop fight isn't even the final battle anyway.
But if you remotely have that thought, you aren't a Zoro-fan and apparently only a Luffy lover. Amazing thought process by this forum. At least you understand that things can shift, because they can and we have no idea if, when or how they can.