There's a few things that make this pretty unlikely. Google doesn't triage or repair the phones themselves, they contract it out just like everyone else. And the people they contract it out to almost certainly have procedures in place which are meant to ensure that neither the devices themselves nor the data on them get out.
I'm not saying it's false, but I would definitely take it with a grain of salt.
That said, before you send any devices in for repair, you should wipe them to the best of your ability. Also, you should set a secure password (PIN, pattern, etc) - even if you set your device to not lock, you can encrypt/require password on startup, which would prevent the repairperson from seeing the photos much less posting them.