New
#331
WHQL has nothing to do with driver signature, that falls on the digital certificate included with the driver. The only time something like what you're referring to should happen is if you install a modded driver that breaks the digital signature. That or the manufacturer was sloppy and forgot to include/update the digital certificate.
Also for what it's worth the new 16.9.1 despite being a hotfix driver is in fact WHQL, at least according to dxdiag ojn my system.