You can’t Bind to Header because it’s not a FrameworkElement. You can make the text dynamic by modifying the Header Template like this:
xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
xmlns:dataprimitives="clr-namespace:System.Windows.Controls.Primitives;assembly=System.Windows.Controls.Data"
<data:DataGridTemplateColumn>
<data:DataGridTemplateColumn.HeaderStyle>
<Style TargetType="dataprimitives:DataGridColumnHeader">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<TextBlock Text="{Binding MeetingName, Source={StaticResource LocStrings}}" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</data:DataGridTemplateColumn.HeaderStyle>
</data:DataGridTemplateColumn>