That may be true, but don't base it on the alleged coins they've found there. I've found Spanish reales from the 1700's here in RI, but they weren't lost by Spanish visitors! Same for all the British King George coppers I've found. Lost by American farmers, not invading British soldiers!
Bottom line, just because they found a Chinese coin doesn't mean the island was visited by anyone from China! They're grasping at straws trying to keep this futile search interesting, but they're doing it at the expense of the truth.