Depends on how you define disastrous. As pointed out several other times in the comments, several commercial activities rely on WhatsApp on several levels.
Even blocking for a few hours causes several man-hours to be spent in setting up alternatives. And lots of telephone costs, as well, since many companies - including those with technicians on the field, sometimes in another state - use that to communicate instead.
Even blocking for a few hours causes several man-hours to be spent in setting up alternatives. And lots of telephone costs, as well, since many companies - including those with technicians on the field, sometimes in another state - use that to communicate instead.