Thanks @Jkramer0327 and @wemct, really helpful. So that's two US 2026s with Drive Assist, both with the camera, neither showing Hands-Free in the Connect Store.
@Wivenhoe agreed, if the hardware is the same, then what's keeping 2026s out is either software/compute or just Porsche policy.
Why...
Update on this: Porsche's US Hands-Free Assistant page now lists the Cayenne Electric from MY2027 (not just the Macan), with Drive Assist required and the subscription free via the Connect Store.
On the hardware question, a 2026 Cayenne owner has confirmed his car has the driver observation...