Question

Then if so, what would the other pokemon do? struggle?

Answer 1

The only possible way to disable all moves would be to activate Imprison between two Pokemon who have the same four moves. This would render the opposing Pokemon with no attacks to use, and would logically induce Struggle until it's KO'd or switches.

Answer 2

Disable only lets you disable 1 move at a time, so unless your opponent knows the same exact moves as you and you use imprison, than no you cant. If you did though, the pokemon would use struggle...