I guarantee you they were tracking. Honestly there aren't too many times - especially in big studios back then - when tape wasn't rolling at all times that instruments were being played. Even when artists would say "I'm just going to practise, don't record this..." you very quickly learned to just say "Okay", and hit record anyway, and so many magic moments would happen in those situations.
And I suspect your hunch is right, and the release is using the demo drums which are pre-NRG. To my ear, the Healing Foot drums sound markedly different to even the in-studio demos from those sessions, leading me to think, as you did, that it's just programmed loops