Would capability meeting records from the Big 4 uk be given to third parties if they ask?

[autisticunemployedbitchparents]

My brother, who works in the Ministry of Defence, mentioned that jobs requiring deep vetting might access my capability meeting outcome letter. This is concerning because the letter discusses my mental health/neurodiversity, and there is a stigma attached to it. The letter also includes my boss, the equity partner, stating that my mental health/neurodiversity does not impact my performance, and essentially calling me a lazy liar.