The list was leaked about 3 weeks ago. After reading through it I realized it was impossible that a random fan could have come out with all those names. The references are way too clever for someone to just "make up" and a trick.
A few days after it was leaked, IGN "revealed" some new English names which matched the leaks. So I published those names on the site.
Since then, there have been many other Pokemon names revealed which matched the list, plus Joe ast Serebii.net posted the list - he never posts anything unless he knows it's 100% legitimate.