Google still know everything about almost everyone, regardless of a switch.
There are browser extensions (for Firefox at least) which show you (and let you choose) the domains from which there are javascript files loaded and executed on every website you visit. I installed one recently and have noticed that about seventy to ninety per cent of websites load assets from one Google domain or another. Couple that with one or two android phones in your vicinity (even if you personally don't have one) or, God forbid, being photographed with one. Send one or two e-mail messages to a Gmail account every now and then. Basically, all our base are belong to Google already. Public pressure achieving this one switch hidden somewhere deep in the guts of Chrome - if it ever has an effect (cf. the switch for the location services in Android) - does one thing only: lulls some more gullible DK's* into thinking that everything is actually quite fine.
* DK for Dunning-Kruger, meaning here those who are a bit above the uninitiated mass thinking they got a hunch when they actually don't.