YOU FELL FOR IT FOOL! THUNDER SPLIT CROSS HOPKICK ATTACK! For real, the idea of the video was that in a real match something that you would never have anticipated or knew existed actually happens. At least, that's what happened to me...
I'm pretty sure that hop kick was in the command list for Steve in earlier games. Strange how certain commands are no longer listed in Tekken 7 and it seems to be the case in Tekken 8 also. Jin and Asuka had moves that aren't listed either.