I have to wonder, as well. I've corresponded with Craig on multiple occasions about this project - even chatted with him personally at his office - and each time it was "production issues", especially that the maker he had doing the HO versions was not capable of doing the N version, with the N version requiring a different design approach.
We also may have to factor the competition emerged in the interim: BeN Scale, Showcase Miniatures, and the recently announced Train Cat product. Signals are definitely a niche interest since cost and complexity are high hurdles, so IMO market saturation would come quickly. So I would not blame Craig one bit if he changed his plans and withdrew his own offering, throwing moral support to the others.
I have BeN Scale signal heads sitting on the bench for one long-procrastinated project, and a handful of the Showcase signals for future stuff. I like the BeN Scale heads for their brightness and the Showcase for their awesome detailing. However, I'm standing by for what Bob (Train Cat) is going to offer before I go whole-hog and buy 55-gallon drums' worth for the yet-to-be-constructed layout.
Since you're modeling the OSL, are the BLMA signals the right style? I'm modeling the LA&SL, which happens to be the prototypes Craig modeled, unusual head spacing and all. So I'm still rooting for Craig to do them, but, again, I have to wonder.