This thread is about Taproot implementation, Taproot was introduced into Bitcoin core in October 2020, but not yet implemented as the implementation is a gradual process. On December 01, 2020, Bitcoin Core version 0.21.0 was released in which Taproot's code was  available for testing. If you scroll up, you will see a post where fillippone posted about it the day Bitcoin Core 0.21.0 was available.