I found the culprit.
The values in the xml file were accidentally swapped (The PHP code is correct).
If you need a quickfix open the templateDetails.xml file and around line 182 locate
<field name="showTitle" type="list" default="yes" label="TPL_NU_BE_SHOW_DATE" description="TPL_NU_BE_SHOW_DATE_DESC">
<option value="yes">YES</option>
<option value="no">NO</option>
</field>
<field name="showDate" type="list" default="yes" label="TPL_NU_BE_SHOW_HEADER" description="TPL_NU_BE_SHOW_HEADER_DESC">
<option value="yes">YES</option>
<option value="no">NO</option>
</field>
and swap it with
<field name="showDate" type="list" default="yes" label="TPL_NU_BE_SHOW_DATE" description="TPL_NU_BE_SHOW_DATE_DESC">
<option value="yes">YES</option>
<option value="no">NO</option>
</field>
<field name="showTitle" type="list" default="yes" label="TPL_NU_BE_SHOW_HEADER" description="TPL_NU_BE_SHOW_HEADER_DESC">
<option value="yes">YES</option>
<option value="no">NO</option>
</field>
