While I don't particularly care whether or not a transition is added in this scenario, I do see your point, Metal. In a levelpack that is meant to follow a story (essentially be it's own stand-alone game), transitions between areas are helpful. But then again, only to people who actually care about the plot. I've noticed that plot is not a key thing among most folks in this community. But some do care (like me, and probably you.)
Heck, I'm so obsessive compulsive about it that the levels in my "The Chase is on" levelpack actually begin in the ending room of the previous level. Like, for example, the boss of one stage takes place in a control room, and the next level begins in that room, with a ventilation shaft leading outdoors to the content of that level.
It just depends what your priorities are, I guess, and while I appreciate that Fawfulfan has taken the time to create a plot, I'm sure half the people who have played the pack don't bother to read it.