No one in BCCI or their granny asked for 80% share at all, ever. According to records BCCI only get 18-22% (depending on taxes) from ICC funds and they contribute approx 70-80% of revenue, this could surpass in the upcoming cycle, once ICC discloses their media rights numbers.
For the 2015-23 cycle, total funds available with ICC, to be distributed to member nations was $1.774 billion. Out of that, BCCI received a share of $405 million, which amounts for 23%. There is no tax deduction, as the ICC is based in UAE (where there is no income or corporate tax).
This is a rough calculation:
2015-2023Inflows:
Media rights: $1.800 billion
Sponsorship and other revenues: $0.700 billion
Outflows:
Grants to member nations: $1.774 billion ($221.75 million per year)
Administrative costs: $0.726 billion
2024-2027Inflows:
Media rights: $3.600 billion (assumed 80% of the revenue from India)
Sponsorship and other revenues: $0.400 billion (very conservative estimate)
Outflows:
Grants to member nations: $3.500 billion ($875 million per year)
Administrative costs: $0.500 billion (estimate)
As per my estimate, the grants may increase by more than 4x. But we never know how the businessmen such as Barclay will give excuses to steal money.