Everything in the universe is spinning. The earth spins around its axis, all the planets spin around the sun, and the sun spins around the centre if the Milky Way galaxy. Despite all this rotation, however, many astronomers ignore rotation in their calculations. The giant gas cloud, like everything else in the universe, is spinning. This is probably because all the gas that makes it up came from stars, which are themselves spinning around the centre of the galaxy.
Angular momentum is calculated by multiplying the rotation speed by the size of the object.
This means that if a spinning object shrinks, it will start to spin faster, and the smaller it gets, the faster it will spin. Springboard divers use this phenomenon to make themselves spin faster, by hugging themselves into tight balls. So, if the gas cloud got larger, it would spin even more slowly, but if it shrinks, it will spin faster and faster. Indeed, if it gets really small, it will be spinning so fast that centrifugal force becomes important, and can balance whatever force is squeezing the cloud. The cloud would then end up as a spinning disk of dense gas, au in radius and less than 1 au thick.