[version_five]

The whole asking Bard thing towards the end is completely meaningless and I'd argue irresponsible. They even say

  But of course, the observation that Bard consistently makes these claims can’t be seen as evidence one way or the other

and then go on to quote a bunch of stuff Bard said.

If I had to speculate, sounds like it could have used anonymized gmail data (could they have some kind of pii removal tool that they run first, that's common, though I wouldn't trust it too much), or something is being pretrained on gmail and fine tuned on something else (hard to see a reason for that). Anyway, google is acting suspicious, but pretending the chatbot's "opinion" has any bearing is disingenuous.