[Shryke]

If the collapsing cloud was gravitationally bound in the first place--i.e. able to collapse--then there's no way for the collapse to generate enough heat to dissipate the cloud.

Doesn't a star that goes nova do exactly that? Forgive my ignorance if this is compeltely wrong.

[Physicist]

Doesn't a star that goes nova do exactly that?

Well, no. Novas aren't powered by gravitational collapse, and they don't dissipate the entire star. Supernovas are powered by gravitational collapse, but they also don't dissipate the entire star, but leave a neutron star behind.