Frozenbarb, I don't know if they can really "run out" of Eco-Complete. Its manufactured. As long as they have the right ingredients, which shouldn't be hard to come by, they should be able to make it.
I can only assume they reformulated for some reason. Somewhat disappointing to some, I guess, but as long as it has the trace elements like they claim, I'm cool with it. My bag still had plenty of 1-3mm size pieces in it, which is the best part about it.