The earth's crust is 8% aluminum.
We will have bigger problems before hitting this one.
We will not remain without gallium, but it is impossible to scale up the gallium production to a higher level than provided by the current productions of aluminum and zinc.
So there is a maximum level of gallium that can be used per year and it would not be possible to increase the production of blue and white LEDs and of power transistors above that level.
Fortunately, the amount of gallium used per device is very small, so it is not likely that we will hit that level soon. A much more serious problem is the associated consumption of indium, for which the resources are much less.
The metal isn't going to disappear, but it won't be concentrated enough to be as easily retrievable.
I'm inclined to think we've lost that gold.