Lipsey's is showing this in their catalog and a dealer in Ohio is listing as being in stock.
Is this really a new run or just cleaning up older remaining parts?
I can't find it in the Sig portfolio. Perhaps if its coming as German made that may explain its not being in the catalog.
Also, I thought the Custom shop in Germany was closed.

From my understanding Legacy sports was supposed to be the new importer of Sig mastershop guns this year and lipseys was the exclusive distributor for them. I’m sure they put the SKUs on their website to get peoples attention and start adding them to wishlists and such. I don’t think they ever received any of them and Sig Germany closed down so I don’t think you’ll see any of these SKUs.

It’s possible some made it here through lipseys (although I never saw any) or MMB so the sku MAY exist somewhere, but I think what’s here is all the will be here.

I took another look at Lipsey's under 'German' Sigs and there are a BUNCH of the former Custom Shop pistols with many of them being listed as NEW but the prices have gone up considerably.
Top Gun Supply in Ohio has a P220 X-Six in stock so some are apparently coming in.

even though the mastershop shutdown, there are many vendors in germany that still have many models in stock for import.