The way I see it (don't take it as gospel)
The first coins we done through a partnership CD & MM, all went pair shaped and sales were suspended.
CD split the partnership and MM continued on producing/selling coins including planned future coins.
Seems like a behind the scenes legal action has taken place and MM who make & sell the coins and operate the SSBS website have been told/ordered/issued legal ruling to stop selling under the SSBS logo.
Now looks like CD has taken ownership of SSBS and has issued a new coin and is calling it the 5th in the series as he had no part/financial interest in what MM did once he left, this being the reason he does not recognize ag47 and so on
D&D 5oz was the final coin in the series for MM
Warbird is CD's next coin in his series
Just my opinion, not sure how true it is