The entire region is a mass of confusion - UAE can't decide amongst themselves if the next callsign is "Dubai Approach", "Dubai Arrivals" or "Dubai" when they transfer a flight onward.
easily taken care of with SUPER, HEAVY, or nothing after the call sign
That wouldn't appear to be enough because they seem to require differentiation between, for example, 200 and 300 series 777s.
The problem with the AOI is it's written by a very cheap provider and therefore errors and omissions are regularly found in it. It's not surprising the AOI missed the fact that ATC wants the ATIS designator included in first transmission. It's not for pilots to decide what's written on the ATIS can be ignored. Blame the Trg Dept - many of these calls are being made by newbs.