While a neat architectural improvement, the cynic in me thinks this is a fig leaf for the voracious inhalation of your digital life they're already doing.
Particularly relevant: "Federated Learning allows for smarter models ... all while ensuring privacy". Reading the paper, Google would still receive model updates, so this statement seems based on assumption that you can't learn anything meaningful about me based on those higher level features (which are far reduced in dimensionality from the raw data). I'm curious how they back up that argument.
At least one person is thinking straight. This is basically a blanket license to learn from everything you do, even if you do it in third party apps. Right now those apps are opaque, and Google can't see what you're doing there. As an ad company (which is what they are, first and foremost) this pisses them off pretty bad. They would like to know which brands you buy on Amazon, what you like on FB and Pinterest, who your friends are, etc. And they want to tie it all to your advertising GUID, preferably across devices and into the real world. The info doesn't even have to be in their cloud, as long as they're the only ones with access to it. It's pretty cool, in a way. It also ensures I'll never buy an Android phone.