[deleted] I just wanted to know if I needed to update a new unboxed Pixel to the lastest version before installing GrapheneOS.
If it's a 6a that was manufactured in the first batch and has been sitting on a shelf somewhere all this time, you will need to update it to get OEM unlocking (as the directions say). Otherwise, as others indicated, the installer will do any necessary updates.
As a general principle, it's not a bad idea to update a new device out of the box while it still has the stock OS. For a laptop it may be much easier to get firmware updated via the original OS. But the GrapheneOS updater is thorough.