China doesn't really need to nuke every single village in all of Europe and USA, they have more than enough to glass USA completely and Imperial Japan as well. Should an exchange happen, it's likely that Russia would butt in on the garden, given they have so many legacy nukes which do not have range to go anywhere else. So I would say that the Euro direction is firmly covered.Problem is, China doesn't have nuclear parity yet. It's gonna take a while to achieve MAD with all those complicit. Even if China's building 60 a year, it would take decades.
Most of American nukes which they declare on paper are legacy platforms that don't have much range or even worse are air dropped bombs. These would not be able to reach mainland China. The relevant nukes are ones which are launch on warning. China isn't bound by any arms control treaty so it simply doesn't need to provide data.
MAD is not number of warhead parity (which we won't even know how many China has anyways), just the ability to destroy the other country completely (hit every major town and larger settlement), which China can casually do to the US.