Based on experience, my working assumption is that with the current well-defined, solidly gated termination of the bikeway, they consider everything beyond that point a no-bike zone. If you actually talk to some horse people and they say otherwise, well... it's your call. Being something of a realist about human behavior, I personally feel like it makes sense to align the tagging with the big, obvious physical obstacle rather than a more nebulous "I don't see any signs yet" approach. :P

But yeah, I doubt there's any danger of construction starting any time soon.