Or close to it. This is actually my son's GL1000. He bought this to replace his first motorcycle, also a 1978 Gold Wing. It has under 30k on the odo but suffered from being parked with a full tank of gas around 2001. In the end we took parts from the other GL, a 100k mi beater, to get this one going. It's a sweet sounding motor, no chain slap, and much smoother running. Now we are doing the shakedown runs before the end of the riding season.
I am no expert, just someone that has messed with this kind of stuff for a long time.
In general it does help, you are minimizing the area that air and moisture can attack the metal of the gas tank. But now here in the US it's hard to find fuel without ethanol and ethanol loves to attract moisture. So I don't know if that advice is as relevant as it once was.
The fuel system on this Goldwing was very old and after decades all bets are off. Old fuel is going to do damage no matter what. If you are thinking in the range of weeks or a few months a full tank is better, if you are looking into the range of a year or more, I actually believe draining the system totally is the better option.amd then storing it in an area with limited exposure to the elements.