As someone else posted on a different thread, look at the hechsher on the bottles. It clearly states that this grape juice is kosher for Kiddush and Arbah Kosos.
If it were muttar for health issues only, the hechsher would need to state that, just as is done on boxes of egg matzah…”Muttar rahk le’cholim oh zikaynim, ki’mivuahr b’Rema”.
Grape juice is yayin, lechol hadayos. That’s why you make a “borei pri hagafen” on it. The Shulchan Aruch states you need yayin for arbah kosos.