This policy removes the regional formats interface from the Regional and Language Options control panel. This does not, however, ...

This policy removes the regional formats interface from the Regional and Language Options control panel.  This does not, however, prevent the user or an application from changing their user locale or user overrides programmatically.

The policy is only used to simplify the Regional Options control panel.

If the policy is Enabled, then the user will not see the regional formats options.

If the policy is Disabled or Not Configured, then the user will see the regional formats options for changing and customizing the user locale.