Setting GPIO pin sate before initialization
I guess, yes. But it could have no real significance until the GPIO is configured. As you might see from depiction, the pull ups are separated from GPIO function, in your application they are no-pull meaning both pull-ups disconnected. The GPIO could be read at any time, regardless of the configuration as it doesn't alter any behaviour, well writing on GPIO however does change it, since it turns on/off output transistors P-MOS and N-MOS. To be able to control the output transistors the GPIO has to be configured as output, but if you write the register before that, you can but it won't alter the physical state of the GPIO, just the output register.