So, in my short conversations with different Honda reps, both local and national, I kind of get some mixed responses, or lack of understanding... but the reason that makes most sense comes from the national source. He said that a while back Honda sent out invitations to current Honda owners whose cars have the Display Audio compatible with CarPlay (this would be the 2015 Civic, Fit, and CR-V above LX - SE for Civic, EX for fit and CR-V). The Accord was not blessed with this at all. The Civic Hybrid does have the proper hardware. The rep said the selection process was random and only a few people, perhaps under non-disclosure of some sort (not judging here guys), as he also said they are keeping a tight lid on this, understandably. So we understand properly, the HondaLink with Aha compatibility is not the same as HondaLink The Next Generation (Display Audio).
With this crowd though, I think they could get a lot more feedback having people actively participate in a beta, but that's a corporate decision, not an engineer's decision ;-).
On the other side, from the local rep, he did say there are a lot of issues with the software, though he made it sound like Apple's problem...which I highly doubt after just spending a few minutes in a test drive with Display Audio. Then he proceeded to say the Display Audio with $100 cabling works great without any compatibility issues. This is likely true since he wasn't really talking about Display Audio and its apps, just the compatibility with the iPhone and Siri Eyes Free, which apparently do work well. Any updates on your end, do share please.