A year ago Anthropic was losing billions per year. I'm sure that if it had listed and then collapsed everyone would've gone "first they run around saying how AI needs to benefit society and then they dump a cash-burning company on pension funds"
Better to dump it when valuation is low instead of inflated.
But pension funds are already invested in them through the VC funds. The only difference is (more) people would be able to invest in Anthropic without paying management fees to middlemen.