I almost imagine they set the minimum iLv as what the lowest someone can join as who is being carried by people of much higher iLv. I can't imagine an ENTIRE party entering most fights at whatever the minimum iLv is listed for, and that doesn't just go for Extremes. Can you imagine a DF PUG of 4 players at iLv48 (meaning wearing worse than AF1) doing the new dungeons and succeeding?