When Musk purchased and rebranded Twitter as X he also unbanned a large number of accounts famed for Nazi and similar race based content.
He has famously thumbs-ed up significant chunks of such content and in the event mentioned here replied to an explicit statement (as outlined about) as being "the actual truth".
He is an unquestionable fan of Nazi like content, many will shrug it off as his grandfather was an actual Nazi fan (having to move from Canada(?) to South Africa because of such beliefs), and his uncle (IIRC, certainly a close family relative) was a senior member of the South African apartheid government.