Board Thread:General Discussion/@comment-26238126-20150409190219/@comment-1639863-20150413230739

If they decide to crossover, and that's a huge if, Titans isn't getting Roy. The Arrow guys like him too much. They've spent so much time trying to develop him that they're not going to give up a main character to some show on another network, regardless if the networks are buddy-buddy.

And that goes double for Wally, who, by the time is introduced and possibly get super speed, will be too developed to be passed to Titans, too.