question....

That depends on the contract you're offered. Check to see if they option the series. If they do (and it can be a very good thing with proper wording,) then I wouldn't. If you haven't been presented with a contract yet, then you might wait until you know for sure. Sometimes the publisher doesn't mind, but I would hate to see it a sticking point in negotiations for the book. Our agent suggested we save our shorts in the same world for future anthologies WITH the publisher. Better money and if the world is a hit, guaranteed publication.

Shorts

While you do have to check the contract, I've never known a publisher to mind the writer selling short stories in teh same world as the novel. Especially pre-publication short stories. Such stories can bring a huge fan base to the novel, and that's a very good thing for the writer and the publisher.

A publisher who didn;t want short stories published would be a very weird creature. On top of this, I'd never sign a contract that took short story rights from me. That would be nuts, and it isn't something any sane publisher would ask you to do. It would harm the publisher just as much as it harms you.