Oh wow, he's resigning not getting fired. There is a difference. He'll still work for SE. Now whether this is a forceful resignation or not that's an entirely different story, and we'll probably never know that answer.
It's also totally up to Wada, if he stays with Square Enix. This is the same thing when Tanaka left. He resigned and chose not to stay with the company. He was never fired. He left on his own accord.