I have a suspect 624 too. Since the recall involved both 44 Specials and 44 Magnums, I assume - possibly incorrectly - the matter is much more relevant to the 629s. (This is not advice - just idle musing.)
I've mulled it over ever since I bought the gun and subsequently found out about the problem. I have always wondered why S&W wouldn't just shorten a 629 cylinder enough to fit in the 624 and send it back.
I suppose since the gun is marked 44 Special, they can't permit that.
I don't shoot hot loads through my 624. Plenty of 44 Magnums on hand for that. So I am still fence-sitting. It is such a nice revolver I can't bear the thought of it being destroyed.