I think you mean the Nikon D300s is no longer being sold in Japan. It is still being sold in the rest of the world and listed on the Nikon USA site. Since Japan passed a law that requires the electrical contacts on LiON batteries be designed to prevent direct shorts when the battery is out of the device it is intended to operate in due to the dangerous overheating of the battery when the terminal are short circuited.
As for B&H "Out of Stock" is different than "discontinued".
Nikon has just been able to get their Thailand manufacturing plants operating at normal production levels, but they have a over a 4 month backlog to fill before the distribution level return to normal.