Yes, and no. That is a big topic that I should write on one of these days.
Short answer is: the "syllables" of Japanese are not the same as the syllables of English, making (in my opinion) sticking to a 5/7/5 count far too long. But you will find both opinions. In both America and in Japan, at any rate, free-form haiku have become far more common than they once were.
Thanks for the clarification. I shall try to do more research on this topic and other forms of poetry too. Maybe even write a post about what I find.