I'll start with the guessing game. My guess is one or both of the swipes that are missing. First is the Super Silver, some of those paid out well to us but if people closed those accounts early the vendor may have balked a paying out such high numbers, some were 8,000 siver and if they got doubled during the first 20 that is a high amount for CN to absorb.
Next that is gone were the gender/age surveys, I have not seen one since the new update.
I don't know what abuse took place. I do know that I have saved all my earnings and used a very small amount each month to pay off a single red pocket phone line. All of my earned "Gold" should be well seasoned enough (older than 4 months) to be available immediately. The earnings rate has been so abysmal over the past few months that I hardly earn anything anymore. with this update, there is less to earn.
The only abuse I can directly point to is that I lost several phone numbers when they moved to red pocket back in August of 2017. I was told and promised that I would be reimbursed and never did receive that credit. I also laddered several accounts so that they were chained referral accounts. A few of them got a bonus for referral credit, most did not then after a couple of months none of them got credited.