Still available on all my recent flights that I can remember. Most of the time it's in the basket during boarding, which is fine with me. I always take one even though I use them on less than half of the flights that I'm on. As a result, all the various carry-on bags I have contain plenty of them.

I typically only use them when flying international J or premium transcon (or basically in a lie-flat seat where I'm going to spend more time eating/using IFE & seat controls/storing personal items, etc.), or occasionally in Y if a seat/tray doesn't appear clean. I probably end up using them on other carriers just as much as on UA aircraft.

They also seem to be holding up very well compared to the ones that AA & AS used to pass out. I still have a few of those left as well, and I'm finding most of them have dried out. Could be because the average age of the UA ones I have are much newer, since AA & AS stopped handing theirs out a while ago.