Yeah that looks like the most probable scenario. Gurman is still saying that an iMac Pro is coming, and Young is still point out to 27 inch displays that are going into mass production. That looks like this panel is for the iMac Pro, not a standalone display. Other than the technical limitations of Thunderbolt, it would not be logical at all for Apple to release a 27 inch display 3 month after the Studio Display, with mini-LED and promotion it would be competing with the Pro Display XDR, which Apple clearly will not discontinue (I don't see them leaving the 32 inch+ monitor market).
But if that's true then the iMac Pro will have a better display than the Mac Studio/Studio Display combo which is already quite pricy. Maybe the iMac Pro will not be getting M1 Ultra? Otherwise what's the advantage of the Mac Studio over the iMac Pro?