The person are probably just using a glitch that THT still haven't fixed. By using that glitch, it will remove the remix sign from the project. It could also be a total remaking, but with that complexity in the project it's more likely that it is a remix but with the glitch. This user has also copied many others, like @CreationsOfaNoob and @MagmaPOP, so if he/she (the user) doesn't have a lot of time to copy projects, it would probably be a remix. THT are working on a fix of the glitch, I think @Montoya or @Rodrigo was notified about this.