Earlier quoted context omitted.
I wonder if this counts as personal data. It's a copy of everyone's name, job title and employment dates. I can certainly see many European businesses would be wary of an employee keeping this list.
Are you referring to GDPR? Does it apply to employees too, or only customers?
A business probably handles sensitive private data on employees (e.g. medical conditions, family records). Employees know this, and could report an ex-employer out of spite, especially if they're aware of poor data security.