I mean... any club that isn't a one piece forging is a "hollow body" to an extent but the fact that the Ai300 is thicker and has a larger cavity removed is what makes it a cavity back. Same with the AiSmoke HL. Callaway wouldn't be calling it a cavity back if it wasn't.
Construction wise you're correct. Interestingly though, the lofts of the HL have more in common with the Ai200 though. And the lengths of the Ai300 match both Smoke sets.