If you read my post at all, you would know that your statement is 100% untrue. The testers have never had any information ahead of time (as JeffT mentioned) because ALL of the information they had through testing was not deployed onto the live server. So, IF 'half your decisions this age were made from leaked beta testers information' then ALL of those decisions were just as well taken from a hat because, once again, ALL information testers had available to them was not actual live game data.
I personally run the test server. I alter the code into the test form. I know the formulas that are being used and only I (and JeffT/Munk) know how to evaluate the data generated from the test server. The gains formula? Never went live on the test server. The personal explore pools? Oh, those had 3 different parts altered. The explore formula? Unchanged from last age so is irrelevant. Paladin never had self spells able to cast on others. None of the paladin self spells were coded to provided any effects on test server. Rituals? Oh these cost 5 runes and 1 cast to initiate, and they didn't provide any bonuses (not that it mattered because the bonuses were public knowledge). So what exactly were you able to base your decisions on from leaked beta testers? You have me intrigued.