The Battle of the Line and the hole in Sinclair's mind was always
intended as the entry point or trigger to the story. It's like Frodo
being given the Ring in LoTR. The story isn't about that, that's how we
get INTO it. Frankly, there's no way you can sustain that one element for
five years, nor did we ever intend to do so.
The only difference in the resolution of that aspect is this: we had
originally intended to resolve the missing 24 hours, and the Battle of
the Line, by episode four, season two. We've simply moved it up 3 eps to
the first episode. Because new players are coming onto the field, in the
form of the Shadowmen, and other forces, and we now have to begin turning
our attention to new mysteries.