Do/did the asteroids contain enough water to create Earth's oceans?
This is far too soon to draw sweeping conclusions. The Philae probe has only measured deuterium for one comet. But comets are diverse, of diverse origins. We need to take a lot more samples, from many different comets, before we can conclude firmly that water has, or has not, come from comets.

The only conclusion we could draw so far from this study is that earthly water has not come exclusively from comets similar to 67P/C-G.

What you're seeing now is the usual distortion that occurs in the media after some hugely popular experiment is completed - its conclusions are blown out of proportion. But that's not how science works.

Let's write this one down, and wait for further science to be put forth. We don't know enough yet about these objects.