You're out of your element, Donny. Every TV show plans ahead for next season, regardless if they know they're cancelled or not. It isn't at all unusual that the seeds of future stories might already be on the minds of the writers before season four wrapped. Lastly, I spent just under a year working with three of the writers from Enterprise on a former job. On the occasions that the subject of Star Trek came up (because that's what they always called it when discussing it), the writing, as it were, was very clearly on the wall and they knew it.