I've flagged similar as a bug to Google. You can use their docs share function to get non-publicly available names from email addresses and confirm if they are

I've flagged similar as a bug to Google. You can use their docs share function to get non-publicly available names from email addresses and confirm if they are an existing email. To test I setup a spreadsheet with randomly generated words and it does grab names for you. Personally I feel a bit annoyed Gmail would share my first/surname to people if they test a non-identifiable email address. Also I believe scams could use this to improve their success rate if they can insert peoples names to false business emails type thing. But according to Google this is 'a feature' not a bug.