No idea ... I'm just guessing. I would expect that a camera with detachable M4:3 lenses would be a good possibility though.
Looking at what DJI have done (by effectively removing detachable cameras from their Phantom range and killing off the Vision+) they have moved the detachable camera option onto a higher price point (the Inspire). This is clever, in my opinion as it adds a distinction to the different ranges. Professional or enthusiast users are more likely to be interested in the flexibility that you can get from choosing different cameras (and maybe lenses) if that's something that does indeed happen.
Ask yourself this, why did DJI make the camera and gimbal modular on the Inspire1 - there can be only two reasons: replacing broken cameras, or future upgrades, surely? I think future upgrades is good business, if you consider that maybe 50% of Inspire owners might buy them, especially if it's priced at a similar price point to the new Black Magic mini at ~£999, which I think is quite feasible.