Yes, but unless all 3rd party drivers can run in userspace (which is not really feasible), Microsoft needs to give vendors the option to install a kernel driver, at which point a vendor can always decide to ship a kernel driver and bypass any restrictions.
Imo, the only thing Microsoft can meaningfully do here from their side is threaten LG with pulling all their drivers if they keep doing this.
Drivers still need to pass certification & get signed. Microsoft does get to reject them.
I can't imagine the group doing this validation is sufficiently manned/funded; it's a cost centre, and the effects of cutting it don't show up for years.