From my prior experiences and past vehicles, I've also found out that many dealers put less than what's recommended, and that's why I've specifically written on paper of 'no fuel up' for my ordered BRZ. It doesn't make much of a difference however I'm just very OCD.
You should be just fine, I'm sure. As others would mention, go ahead and follow the break-in process and burn the fuel as you normally would so that you can focus on your next fuel up with the correct octane.
No worries, partner.
