With no inside knowledge of this team or feature, this appears to be almost the exact same feature MS shipped in the IE6 betas over 20 years ago, though without the ability for 3p to integrate with it:
Excellent historical perspective. So many attempted and discarded ideas are being rediscovered/tested to see if they make sense in the current environment.
I expect someone to re-attempt a browser with built-in ads like Opera used to have way back.
https://en.m.wikipedia.org/wiki/Smart_tag_(Microsoft)
https://stackoverflow.com/questions/2167301/what-is-the-purp...
https://alistapart.com/article/smarttags/
Response was extremely negative and the feature was removed. The only thing remaining is the opt-out meta tags all over the web.