#2 - Why it exists
Okay, at its most simplistic, the reason behind this account is most likely storyline progression. This is the next logical step.
It just makes sense. Why would you have a hacker storyline on television and not utilize social media to progress it further?
IMPACT Wrestling recently did so very effectively with ICU, which would be revealed as Sami Callihan. ICU used Twitter, as well as interrupting popular YouTube videos from third parties.
However, the timing is interesting. It may be purely coincidental, but false Twitter accounts have been appearing either claiming to be the WWE hacker, or threatening WWE in an apparent attempt to simply gain followers and notoriety for a Twitter account.
While none of them have been really successful, it just makes sense for WWE to take the bull by the horns and pull the trigger on moving the hacker onto social media.
Even a dormant account would make sense purely to disrepute any cheap imitations, and to control the environment of the hacker storyline, but it also opens up so much more...