Been that way for 3 years now.
Right now I am looking at my 9/12/2011 "Mt. Whitney Wilderness Permit" and I can see:
Entry Trail: Main Mt. Whitney Tr.
Exit Trail: Main Mt. Whitney Tr.
Today on the https://www.recreation.gov/memberSignIn.do?mode=submit
I can see only
"Exit Point: Mt. Whitney Zone- Day Use All Routes
Does it mean that after I have this "Day Use All Routes
JM34.5MWZ" reservation, ranger at the Visitor Center would put a specific entry/exit trail on my permit?
Until 3 years ago, day hikers could go up the North Fork Lone Pine Creek, all the way to the Mt Whitney summit and back, without a permit. Inyo noted some human impact issues in the North Fork drainage, and increased numbers of people going up that route, and as a result, began requiring Mt Whitney day hike permits for anyone hiking beyond Lower Boy Scout Lake. (Interestingly, the areas of noted impact were below LBSL.)
So now, your day hike permit to hike the Main Trail to the summit also is what is required up the North Fork (Mountaineers Route) for a day hike. I don't think anyone changes anything on your permit when you pick it up.
To backpack and spend a night in the North Fork, a different permit is required, which is outside the lottery system. These permits have a quota of 10 hikers per day, with 6 reservable up to 6 months in advance, and 4 available to walk-in people at 11 AM the day before the hike.