One thing they really, really need, and this comes up every time there's a situation like this, is an official corporate Twitter account, blog or newsfeed for Euro Disney SCA. That way they could easily provide a company statement regarding the issue, which might not be suitable to post on the guest-focused @Disney_ParisEN/@Disney_ParisFR accounts. They've both been deathly silent today despite advertising the Meet Mickey Mouse opening ceremony yesterday - it could have been good to at least note the postponement, for visitors who don't follow the fansite accounts...
At this moment, it's really impossible to say how long this may or may not take to be resolved.