It already happened this arc with rooftop piece and the yonkos. Zoro was just a little extra for a brief period of time, bc he was introduced with the supernovae in sabaody.
Gotta throw some bones for the SN's. There was never talk about each M3 member taking down an individual Yonko as if they were a single group (ZKK is another story).
The Admirals, on the other hand, that's some REALLY old expectation.