This is an old news all tied one tweet of his. Its not even a tweet that literally says he will take bitcoin to 1000 dollars neither, he just stated that "bitcoin at 1000 dollars doesn't phase me" as in he needs to make his coin as the real bitcoin cash and willing to spend money to make that happen which means he will have to sell his bitcoins to create funding for his bitcoin cash war and that would result with bitcoin going down of course.

He didn't do it later on, he gave up on the war because he realized his coin will not win and he spent all that money for nothing and even if he kept on doing it there was no way of him winning because after a while even if you can pay a billion dollars to make your dream come true if there is no one that can deliver that hash for you then its a futile attempt.