If you include the next few sentences it's clear that there was no suicide:

    In the wake of Flappy Bird's demise, rumors spread. Nguyen
    had committed suicide. Nintendo was suing him. He'd received
    death threats. His refusal to speak fueled the speculation
    even more.

It's a list of the rumors that were going around, and is terminated by a statement about his refusal to speak (at the time) which strongly implies that the suicide rumor was, well, just a rumor.