None of this makes sense. I highly doubt that the Borg were going to have Locutus start committing mass r---, they were going to assimilate the Federation in typical Borg assimilation fashion. Not to mention this goes into disturbing territory if Locutus was intended to create new Borg this way.
There's no way that Locutus was supposed to reproduce with the Borg Queen in this fashion either. First Contact implied she doesn't have any biological, er, equipment down there. Her fling with Data was emotional manipulation, Data's not capable of biological reproduction. Furthermore, even if she was somehow able to biologically reproduce, we know she couldn't be bothered when at the end of First Contact it showed that Picard was shoved aside in favor of the non-organic Data.
It'd be hilarious if Sisko, with a stunt double actor, was seen being dragged away for medical care after the heroes presumably rescue Tuvok and the other Starfleet officers the Changelings replaced. They'll just have to show him from behind and refer to him as Sisko in dialogue.