Both will take a hit short term and perhaps steem will recover. I am sure there will be plenty of cross posters to add some content volume, but who will stay and vote on them is a question also
The negotiations never really needed to be aided. Once the centralization of the chain became an option, it should have been rejected utterly and completely.
My guess is the same that there will be lots of cross(double?) posters. We will see whether that would continue in the long run, though.
It will depend on value. There will always likely be some that will look to milk from as many sources as possible, but I have found that the ones who are looking to build homes, generally focus more on one platform - and they tend to be the ones who are also producing quality. Though, if there is an easy gateway to crosspost, perhaps more will use it.