Like it says at the end of the article: A lie can travel halfway around the world before the truth can get its boots on.

At least both of those threads contain a healthy amount of skepticism in the comments

It is, because of SynthID.

Checked it myself: https://gemini.google.com/share/825ee3c53dd8

More info about SynthID: https://deepmind.google/models/synthid/

this is exactly how gemini synthid works and how you are supposed to use it

https://support.google.com/gemini/answer/16722517