Fear mostly comes from a lack of awareness – they don’t know how they are going to be personally impacted. Every day they don’t know that and/or hear information from the grapevine creates more anxiety. This results in a loss of productivity as they have no desire to contribute towards the goal.
Making sure you have a proper Change Management plan that identifies individual and group concerns and takes up to address them through a combination of clear communication and messaging from people they trust, getting additional knowledge and tools, support infrastructure to got through the transition, etc. can take care of these.