Calc section, about default cell styles: Default cell styles are loaded from a file in the user profile
AFAICS styles.xml is located in:
C:\Program Files (x86)\LibreOffice 5\share\calc
platform windows 7 & Version: 126.96.36.199 Build ID: 7074905676c47b82bbcfbea1aeefc84afe1c50e1 CPU Threads: 2; OS Version: Windows 6.1; UI Render: default; Layout Engine: new; Locale: fr-FR (fr_FR); Calc: group
Where is the mistake: implementation or release notes?