Just wanted to report that I received the 6.0.1 update today on my A9.
I'm not sure when exactly this came out, but from a brief Google search I found that Android One devices got theirs first around the end of November, and then mainstream Nexus received this update around the first week of December. So at least for this first Android numbered update (there was a security update pushed out a couple of weeks ago) HTC was able to somewhat back their claim of 'Android update 15 days after Nexus', which is a part of my consideration in getting this phone. Let's see if they can keep this up (and also, for how long, because unlike their flagships, HTC never promised to update this phone for two years, just that it will receive a quick update).
About the update itself though: yay new emoji! :/