The guy at least deserves a fair trial in a court of law before releasing him and ruining his career but then again maybe the WWE could do without the bad publicity as to be honest he wont really be missed much bit different if it were someone like Cena or Reigns.
Some thoughts here:
1) Not quite a direct analog, but worth expressing: I'm a public school teacher and the Dept. of Ed.'s policy, like-it-or-not, is for all employees to immediately contact their supervisor if they're arrested. Hypothetically, if I were arrested and found completely innocent of whatever the charges were, I could still (justifiably) be fired for not disclosing the arrest or the charges.
In Enzo's case, according to speculation, he didn't reveal that he was being investigated. Imagine you're WWE: Enzo is holding one of your championships, he's featured in ads for your live events, he's engaged in media appearances, and suddenly you find out that he's being investigated for *rape.* You've had no opportunity to get ahead of the situation, counsel your employee, or protect yourself from a PR nightmare. Enzo's actions were highly irresponsible and would, to me, make him an incredibly unreliable employee, regardless of whether or not it turns out Enzo is innocent.
2) Laws do not correspond perfectly with corporate policies. You wouldn't go to prison for sexual harassment at work, but you could, and should, still be fired if you engage in that type of behavior. His "fair trial" should happen, but WWE is free to employ any policy they deem necessary to maintaining whichever standards they choose to uphold.
3) WWE may also, somehow, be able to tell which way the wind is blowing in terms of the investigation. However, in the event that Enzo is cleared, perhaps he gets another shot. Until then, Enzo should probably start turning out the lights and turning off the televisions in his house while he's out so he can pay for counsel.
Also, if he's guilty, this is still rough news for WWE. I've been expecting the current attitude towards sexual harassment and women's issues to touch WWE, but this is like a sledgehammer. Good thing they wasted no time getting ahead of the situation.