Interesting - I had noticed the omission, but I had assumed that meant that jemalloc had emerged as the agreed-upon allocator best for production. Are you aware of any recent published experiments with the two?
I think tcmalloc vs. jemalloc is basically a wash. One is written by google people and the other is written by facebook people. Facebook is much more forward about their open source project than is Google, so more people have heard of jemalloc.
And the other side of what I was trying to say is that for Google it's largely an issue of personality. tcmalloc is Google's malloc. JE works for Facebook. If JE worked at Google I'm sure Google would just use jemalloc.