Google's head and director of its Android and Chrome division took part in a media outlet's podcast during the I/O event this year. In the course of the interview in question, the two executives confirmed openly for the first time that Fuchsia OS does in fact exist. However, it was also subsequently dismissed as an 'experiment'.
https://www.notebookcheck.net/Fuchsia-OS-officially-exists-but-not-as-you-may-think.420513.0.html