A restructuring is usually judged a success or failure within the first fortnight, and largely on the basis of who resigns voluntarily. The people most able to leave are generally the people you were counting on keeping.
Decide the destination before you speak
Announcing a change you have not finished designing produces months of uncertainty, and uncertainty is what drives good people to answer recruiters. Before anything is communicated, you should be able to state the new structure, who reports to whom, which roles change and what the timeline is.
If you cannot answer “what happens to my job” for every person affected, you are not ready to announce.
Say it before the rumour does
Information moves through a company faster than any communication plan. Once staff learn about a reorganisation informally, everything you say afterwards is heard as a response rather than as leadership.
Tell people directly, early, and in person where it matters. Be specific about what is decided and honest about what is not, with a date by which the open parts will be resolved. “We do not know yet, and we will tell you by the fifteenth” is far better received than a reassurance that later proves untrue.
The legal order matters
Consultation, notice and any collective obligations have a required sequence, and steps taken out of order are difficult to repair afterwards. Termination decisions communicated before the required process has run can convert a manageable change into a set of claims.
Map the legal sequence alongside the communication plan, and let the slower of the two set the pace.
Keep the people you decided to keep
Finally, be explicit with the staff you are retaining. In the absence of a direct conversation, a competent person watching colleagues leave will assume they are next, and will act accordingly. Telling them clearly that they are part of the plan costs nothing and is routinely forgotten.