None of the ones I've seen had, or at least used, indexed shifters. I assume that the indexing doesn't work well for the long cable runs that tri bikes use, with bar end shifters at the end of the aerobars.

There are a couple of indexed systems out there that should do the trick nicely, and with tri guys tending to be equipment happy anyway, I expect there won't be many friction shifted tri bikes around a few years from now.