I don't know if it is a bug or there is some reason for that.

When I create a condition for Data Role(& Save VDB) and then remove the condition(& Save VDB) Teiid Designer doesn't delete whole <permission> tag only the <condition> tag

For example:
Before removing

<permission>
<resource-name>Products_view.PRODUCTDATA</resource-name>
<condition constraint="true">ISAMEXINT=1</condition>
</permission>

After removing:

<permission>
<resource-name>Products_view.PRODUCTDATA</resource-name>
</permission>

I my opinion Teiid Designer should delete whole <permission> tag and leave nothing behind, in case this tag contains only <resource-name> tag