Pretty sure the Pilots would be talking with the lead F/A through the intercom system following a go around.. who should then inform the cabin of what is happening... is this not the normal procedure?
Not at all. If it was a go-around for something like windshear, runway incursion etc, a short reassuring PA from the Captain is all that is required. You do the manoeuvre, clean up as required, complete the checklists, sort out your next plan (diversion?) and then give a short PA. If I was diverting, I would call the CSM first to explain the details, if going for another approach, just a PA to the cabin.
If there was a serious non-normal situation, like gear failure or something, then I would brief the CSM first (the old NITS briefing) and then give a PA (followed by CSM cabin prep PA).
I would NEVER get the CSM to give a PA regarding the technical aspect of a go-around.