US- No, they're not required (or expected) to support unionization. There are specifics about how they're allowed to oppose it (saying "unions will hurt the company" is fine, saying "if you organize we will fire you" is not).
That said, it's still newsworthy. Forming a union is usually a battle of public opinion. As an organizer, it's likely in your best interest to say "hey, look your company only wants to explain unionization if they can help sculpt the message" as exactly the sort of behavior that would drive you towards having a union.
TL;dr- Unionization is frequently about optics, and these aren't great optics for Google.
That said, it's still newsworthy. Forming a union is usually a battle of public opinion. As an organizer, it's likely in your best interest to say "hey, look your company only wants to explain unionization if they can help sculpt the message" as exactly the sort of behavior that would drive you towards having a union.
TL;dr- Unionization is frequently about optics, and these aren't great optics for Google.