Have a search through AICs and GASIL (do they still have those? I've been out of the GA scene a while now). There is some good material on carb icing in general.
Depending on where you are in humidity/temperature/throttle setting carb heat can make carb icing more likely rather than less so.
Your quote doesn't sound very comprehensive though, in its rationale to fly an approach with it OFF, there's at least one concrete reason (the need for immediate full power for a go around) rather than one somewhat situational reason.
Caveat: All the above should be viewed with great suspicion as I haven't flown a piston for over 10 years (and I was crap at it then).
pb