Is it because they found technologically better+better shape mouses (doubt it), or because it's just a matter of sponsors/less trouble to set it up on lan due needing the custom drivers for 500hz etc?

These are the mouses I found from pros in QC.

Edit: Actually apparently Cypher still using a white WMO:

So is he playing at 125hz? I heard they dont allow custom USB mouse drivers in tournaments so??

Edit2: I found this which is supposedly updated:

Most WMO users seem to have migrated to FK2. Is it a proper WMO replacement?