Yeah, I'm not sure what actual problem WotC thought they were solving with this approach.
I have been part of a roll-out of a big announcement in the past that someone did jump the gun on (only about two hours, but it was before a big global livestream). My boss lost his mind because things were no longer under his control, but it just amounted to a bit of hype done by a third-party. There was no actual harm done to us, other than my boss' blood pressure.
Now, if they were having trouble figuring out where the leak occurred -- and shame on them if they don't have internal practices that make it easy to narrow the suspects way down -- sure, make contact. But as I said previously, they should have approached him as fellow fans and talked to him about how they all want what's best for MTG and see if they can get the info from him in a way that wouldn't have him screaming and yelling about his treatment.
But at the end of the day, what was the actual harm that this guy did? He previewed some stuff early. Did he deter sales that were otherwise going to happen? Wouldn't those people have been deterred when the sets hit the street legally anyway, once customers started posting what was in the set then?
In any case, I guess we now know where the person behind the OGL fiasco was transferred to.