From todays blog entry:
What’s happening with Anbox?
We definitely want Android App compatibility, but it is not our highest priority for the moment. Since there’s so much to be done, it will also probably not land for 15.04, but we’re looking forward to playing around with it on the soon-to-come 16.04 images. It is important to point out here, that we still need top push for native apps. Anbox will just be a way of getting crucial android apps that don’t exist on Ubuntu Touch otherwise to run, similar to Wine on the Linux Desktop. The experience will probably not be the same, but it will help eliminate the immediate need. Apps like WhatsApp, Snapchat or Netflix will probably not be ported to Ubuntu Touch, so it makes sense to run them in Anbox if it’s possible.
Why is Anbox needed? Can’t you just use Dalvik from the Android container?
It’s not that simple. This would require us to build compatibility with the Mir display server and all of the userland, it doesn’t work like that.
Also, we don’t want to be android! We want Ubuntu Touch to be a GNU/Linux distribution for mobile devices, the Android container is just the way for us to get hardware access and we don’t want features to depend on it.
https://blog.ubports.com/qanda/2017/06/14/community-update.html