Now, it appears this average monthly "donation" per person has been implemented on each Cong.
Actually, this arrangement has been around for a number of years. The amount is 'suggested', which means the local body decides to send more or less than that. For e.g. my congregation which has quite a lot of wealthy families sends four times that number, whereas in the neighboring city, a congregation sends just a quarter of that donation. Many JW's send contributions directly to the branch offices through the website.
One of my friends from Bethel says that there is no shortage of money pouring in as there are more than enough wealthy JW congregations and families to keep the organization floating.
Until the core membership is strong, the GB doesn't care how many PIMO JW's on the fence keep falling off. There's not much money that comes from the PIMOs either ways as most stop contributing and just prod along for their families.