I just got back from park headquarters and a productive conversation with "Teagan".
https://home.nps.gov/glac/learn/news/meettheteam.htm
Scroll down.
The issue is a "water quality" problem at Goat Haunt.
The Park Service must have a qualified water tech at Goat Haunt to operate and maintain the clean water system there.
Otherwise they can't open the Goat Haunt facility to anyone, including park staff.
The boats will not be allowed to drop anyone at Goat Haunt, not just backpackers.
The US Border Patrol staff are not affected and will still be there.
Teagan said they are trying to get the qualified person on board asap.
They are well aware of the planning issues folks like
OhioGuy have and they hope to have a statement out before the backpacking lottery on March 15th.
She said that qualified people for this position are hard to find and hire.
So that's what's going on.
Backpackers will still be able to hike in on the 8.5 mile trail as discussed above.
Have your passport since the U.S. Border Patrol will be there in any case.
pete
EDIT ADD:
OhioGuy, you don't owe me anything. I like helping out chatters when I can.
I'm glad I was able to talk to Teagan in person.
When I arrived the main entrance office was closed for renovation with a note to call the main number.
But then it said if you didn't have a phone to knock on the door at the building's south end. So I did, and Teagan answered the door.
She was busy on the phone but when done she was really nice.
Not knowing who I was talking to until later, I thought I might get a bureaucratic run-around non answer.
Instead, Teagan was really great and explained the situation in much more detail than I ever expected.
I see now why she holds the position described in her mini bio in the link above.
Teagan is "top drawer" in my book. GNP and the park service are lucky to have her.