To elaborate, Google is making improvements to its environment, the OS,through its memory management by putting a clamp down on unlimited memory access from 3rd party apps by limiting what they are permitted to do. G
All back end processes are now front end processes. Nothing is hidden. No secret instructions to allow locations, contacts, etc. And ads! Google now has channels for that.
This is where the odd pop up ads come in. To be more clear, it is a third party pushing these ads to you, someway, yes, but it's no longer necessarily through the app by its own pop up the third party has control of. It can't. No hidden instructions. So this is Google giving certain methods by way of ad personalization and delivery. Which is set on yes at default by whole load of windows and hidden menus. So, third party apps and sites can send ads to users of 'interest'. I dunno. Logistic stuff, but that's the gist.
These are the upgrades and security improvements to Android, some features delivered in parts like browser and Google app integration. All managed by Google logistics. Ok Google.