For those who don't know what India's prime minister is doing, please read this. It is just part of Swachh Bharat Mission - https://www.gatesnotes.com/Development/Indias-War-on-Human-W...
Without having more certainty than is warranted, it seems plausible that Bill Gates took Prime Minister Modi's word at face value, even though it was apparently all political bluster, and he should not have.