It's not only for testing, it's for familiarizing the people with the map.
If you take a look at the map, you'll know what I mean - no regular towns, lots of special objects etc. It takes a while for people to adjust to "think different" if I may quote an Apple slogan here. And, if I may be so bold, this is absolutely the best map in AH2. Ever.
And to add to the confusion, I think the Pac is the least popular setup here. Always no players on arena when PAC is on. At least I avoid all PAC setups like plague, since the Japanese planes are such underdogs, usually. If anyone asks me, Pac may be skipped altogether in AvA setups.