Yes, and it bothers me a lot, even if it's in an iframe, that it has my real name from my Gmail account inside the unrelated third party pages. I do not trust Javascript iframe policies from preventing the host sites of exfiltrating my name from the Google signin frame. Javascript and browser exploits have a long history.

This uBlock Origin rule blocks the popups at least:

##iframe[src*="accounts.google.com/gsi"]