I’ll prefix this by saying that I am not an Ansible developer, but I’ve been involved in some of the discussions around this. I’ll also note that I haven’t looked at the Mitogen/Ansible stuff in ~6 months.
The Ansible devs as a whole like many of the general ideas of the Mitogen/Ansible work, but it’s unfortunately not very compatible with Ansible’s current architecture. While Ansible’s architecture could be reworked to take proper advantage of the Mitogen work, it’s probably not worth the significant effort. It’s far more likely that various bits of code (or just the concepts) will be cherry-picked into Ansible proper to get some performance improvements.