I personally don't hear any similarities between a young Michael and whoever the lead is on "Heaven Is In Your Arms".
Another thing worth noting, the backing vocalists on "Heaven Is In Your Arms" are female - there are several back-and-forth verses and sighing/swooning noises that give this away in case you can't hear it in their voices:
Lead: "Girl, without your love I would surely die"
Backing group: "Boy, I'm gonna keep you by my side"
Lead: "Believe me girl, this is no lie"