A reddit user thinks there could be a more mundane reason for Twitter:
It was linked automatically to a service desk and the user contacted Gox about it - so he thinks they are just setting up their Twitter differently.
http://www.reddit.com/r/Bitcoin/comments/1yrqpm/mtgox_deletes_all_tweets_from_their_twitter_feed/?sort=newEDIT look for:
[]Delerium69 1 point 1 hour ago
Actually i mentioned this to the support management last week about it not being fit for purpose. Looks like they've listened.
Our service desk system was linked directly to twitter meaning that anytime anyone tweeted us, it created a ticket and was responded to via twitter when we resolve the cases.