Is it a loop interview? I’ve been on interviews where the hiring manager is a gatekeeper at the end and decides if they should send you on 1-2 more interviews or not based on feedback from the others throughout the day, thereby completing the loop. Way back in the day I had some loops I never quite closed at Microsoft that ended with the hiring manager sending me off into the sunset mid-afternoon.
If they work very closely with the VP’s vertical, they might “belong” to you/your big boss, so the interview could also be to answer the question of whether they think you would be good at working with them to build out your future team.
Honestly, could be anything at that level.