I expect that process to be mostly automated, I wouldn't expect the MS folks at the testing lab to do much (if any) manual testing, especially for a new version of a previously approved driver.

I'm not surprised that the driver got approved, especially if the previous versions already had some user UI and this update "just" added the ads. What I would hope now is for MS to either pull the updated driver or ask LG to roll the change back themselves, possibly under the thread of pulling their drivers altogether (iirc they done that with other companies in the past).