Strike Industries has announced on its Facebook page that they are working to introduce SIG P320 frames. So far they have shown only one picture of their frame prototype. It looks to be a 3D printed one of a carry size SIG P320.
Strike Industries also said that there will be more than five models available with many unique features. Whether these will be different size frames or different style ones is not specified yet. They have also promised to introduce a lot of other SIG P320 parts.
Let me remind you, that the serialized part of the SIG P320 is not the frame but the inner chassis. It means that from the standpoint of law, the frame itself is not the firearm. It is just a part that can be replaced on the same firearm.
WIth the US Army adopting the SIG P320 as their new handgun, there will probably be more and more companies offering parts and accessories for this handgun. Not that it will become the next Glock in terms of the amount of aftermarket parts made for it, but there should be a higher interest in this firearm. I also think that the military adoption of the handgun will significantly boost the civilian market sales. I believe there are many people in the civilian market who make their purchase decision based on what the military or law enforcement use for their needs.