I haven't been in ads there in, like, over a decade and some but I believe what was under threat here was specifically Google's ad exchange network. Basically third party bidding for space in Google's display ad network. Basically a part of the business which sells excess "inventory" and which is a much smaller part of their ad business than AdWords and AdSense. Or whatever they call these things now.

I used to work in AdX (and AdMeld that Google acquired) but not since 2014 or so. I believe the AdMeld acquisition itself was one of the things under the microscope here.