The first problem with PolitiFact’s argument is that it misstates the meaning of the relevant language of the bill. That language doesn’t “prevent” the education secretary from imposing curricula; rather, it merely states that the bill shall not be interpreted to authorize such action (a much weaker proviso). Although it’s an issue for another day, plenty of folks argue that education secretaries have been disregarding similarly weak constraints for decades.
But even if PolitiFact had correctly described the bill, the argument would be a non sequitur. DeSantis never claimed that Biden’s education secretary would formally “impose” curricula on the states. On the contrary, DeSantis said that CSDA would allow Biden to “buy off” states with grant money “if” they teach CRT.