Robin comes with an unlockable bootloader and open source drivers.
Root access won’t be enabled out of the box, but with an unlocked bootloader, you can do whatever you want with your Robin. Enabling root access doesn't void your phone's warranty.
Important: Please note that flashing your phone with a custom ROM means that you should not take any of the Nextbit OS updates that delivered over-the-air. Instead, you should update your Robin using the software images provided - see full instructions here. Additionally, this will remove all your Nextbit OS smart storage settings and/or capabilities.