My take on this arrangement after reading several posts is:
1- The WTS can project the future income they are getting for any planning purposes/investment - that’s why companies like subscription services, they are the best business model - steady stream of money.
2- By taking the surplus from KH accounts, the congregations technically are poor and would always rely on the WTS for any funding - More control on KH
3- With the new CO arrangement WTS cuts any Organisational ties with the congregation - elders are not appointed by them
4- If a money rich congregation had paedophile among them and there was court case, the court cannot link to WTS (check point 3), and cannot sue the congregation because they don’t have money!