Not necessary today, agreed.
But...in some future time where more guests are (by necessity) standing in standby queues for extended lengths if time, those stories could prove to be quite welcome diversions.
I've been thinking about it a but, and I think Indy at DL could be seen as the first NextGen style queue. Long standby queue with loads of interactive elements and visual treats. They knew guests were going to be in that line forever, and so they did what they could to bake the wait bearable.
Now, looking ahead to the implementation of the new FP system, I see a similar trend. Pile as much story and stimulus into the queue to entertain the guests that will be spending long stretches of time there.
They aren't adding story for fun, they are adding it to address a foreseen need.