Well, according to the link, bulk 400 ISO is also gone.
Only 36/24 exp left.

This is a little weird, as I have Tri-X dated well into the 2014's, but it may be that the axing of Arista premium is due to a transitional phase, until the film division has been sold/separated from the rest of Kodak.
I know that a lot of people use the Arista stuff, so I thought it might be interesting.