The newly announced The Black Series 6-Inch Moff Gideon, Greef Karga And Kuiil figures will be available for preorder today at various retailers. They are not Exclusive. This includes Hasbro Pulse, Entertainment Earth, Amazon, and Etc.
Here is the Entertainment Earth landing page link for all The Mandalorian Products. The new The Black Series 6-Inch Figures preorders should be listed at 4PM EST.