Earlier today, in our forensic analysis of the SpaceX IPO, we said that according to BNP estimates, the company's inclusion into the S&P 500 some 6 months after the offering would unlock $13.4 billion worth of inflows. It turns out that that is not going to happen 6 months after the IPO. In fact, the earliest it may happen is 12 months after Friday's break for trading... and realistically well after that. That's because after the close today, S&P Dow Jones Indices said it would keep its existing eligibility requirements for main benchmarks…