The weightloss can have a natural explanation.
He lost weight during his last weeks and that time he also began to go to more rehearsals.
The rehearsals were long and he used much more energy when he was dancing than he got from the food.
He used to lose weight during his concerts, it was only rehearsals and he didn´t go for 100% now but I think he had to work harder for this is it than for other rehearsals.He was skinny from the beginning and didn´t have to lose so much weight to look that skinny.
He needed to eat like a hungry teenagerboy.
I think fans said he didn´t walk to the car last weeks, he was too weak, but it could be that he knew he had to save his energy.
When the rehearsals was over he had to do concerts for about 2 hours and not every evening, I think he had put on some weight than.
At least I believe he had been all right.