So this is weird and kinda creepy.
Our family has a condo, and a friend is staying there. I had emailed to get the reservation with the condo company for them months ago.
I was just now searching on Google maps, to send a maps shortcut to the condo. MAPS is saying Here's where you are staying for your reservation from Mar 30 to Apr 5.
Since the reservation isn't for me, I didn't add it anywhere. Google pulled it straight out of my gmail correspondence. (They provide a link to the email in the notice as you can see.)
I suppose it's useful, but also disturbing that it pulled that out of just my email text without my knowledge or consent! And that means something in the Maps group has access to do very deep diving and searching into my personal emails.
Even digging down and finding the Account Permissions, Google Maps isn't even in the list.