Is this a precedent that Google or any company wants to have, though? Engineers with access to company-wide tools or extensions can put political or divisive content into them?
This is more than just a "poster in the cafe" because of the reach and invasiveness of the approach.
Disclaimer: I work for Google, speaking for myself only.
This person chose to have their free phone from the company as their personal phone too. This is completely optional at Google, a really nice perk, and it's made very clear that anything under your work profile will be wiped if you leave.
They will not wipe your personal phone or your personal profile on your phone. This is completely avoidable and shouldn't come as a surprise.
I can't recommend this book highly enough. This is the best book on tech leadership I've come across and I've read a lot of them.
It underscores the importance of NOT trying to solve problems for your team. Instead, help your team learn to solve problems on their own--so you don't become a bottleneck to getting things done.