I talked with Connecting Threads customer service in February as it seemed they were out of the Cone Thread for a such a long time. What I was told was that the Long Shore man's strike had containers on the dock with thread and until the strike was settled a lot of their thread would remain back ordered.
I think that I heard that the strike is finally settled. Connecting threads now estimates according to the website 4-22 for the threads to be back in stock.
So perhaps that explanation is why so many companies are out of thread? Just a thought.