I saw Jay Foreman mention it briefly in one of his videos, stating that it's a heavily debated theory, but what are the evidences that point to it being true or not?
If he did indeed say it's 'heavily debated' then I have to say I'm rather disappointed in Jay Foreman, as this notion is about as 'heavily debated' as the idea the Earth is flat. This claim originates exclusively from the late Gavin Menzies, whose work is not remotely credible and which also serves as the vehicle for a number of racist theories, including deeply offensive claims about the origins of the Maori. I discuss these issues in this answer.