Hey there, cheers for taking the time to post. The reason that we haven't released AR yet is purely down to the fact that it's not on a state that we currently find acceptable for release.
We've put many years of development into this project and spent many of those years failing and refining the experience so that when it's released people will enjoy it. With all that being said, I feel no pressure to release AR. It's a project that I like to work on in my spare time that I'm passionate about. I know that there will always be people who will want to play it at the end of the development journey, so if we can achieve the goal of making something polished and fun to play, I feel it'll have a lot more impact than something that appears half-baked and with a bunch of things that don't work, are represented by placeholders and aren't up to the graphical quality of our other projects.
With Reborn, we've been in a perpetual cycle of re-releasing the same game with minor tweaks over the course of it's lifespan. Recognising that Reborn is nowhere near as polished as it should be, we have taken steps to completely overhaul it, but unfortunately this takes time away from AR. I'm currently not working on AR because I've committed to getting Reborn out of the door. But once that is done, I'll be heading back to AR full time.
As mentioned previously, I feel that a half-baked release would not be viewed favourably and I would feel very disappointed and demotivated as a developer if the game that I had spent so much time working on over the years, released in a state that I was nowhere near happy with. I'd rather spend time improving the game further so that when it does come out, it isn't played for a week and then forgotten about.
The way AR has been used over the years is also like a bit of a test-bed. Some mechanics that now feature in APB and Reborn were originally features that were developed for AR, so when we have the time to develop it, we usually do some awesome work.
As @moonsense715 says though, he's the only one who is working on AR in any capacity right now, because our focus on a team is getting Reborn fixed and out there. If we had more developers, we could work on these two projects concurrently, but right now we just can't. I hope this post answers your questions!