Yup, they just dry out like that. I just try to ignore the brown dry part as much as I can, eventually it will all dry up and just need to trim it. My Nepenthes did that too, especially when we were away for an extended period, I guess it got dried out longer than it should, but now we are back so carefully nurturing the plant to make new leaves and eventually the newer pitchers. It is doing better now, new leaves are out, and I see new pitcher growth too. I also see that it is the older pitchers that are heading out, so similar to most plants, the older leaves drying out first.
I have seen in a youtube video where one grower just cuts off the brown upper part, and just maintain the still lower green part, since it is still attached to the main leaf, and still does some photosynthesis too.
