There is no longer a need to add these portlets manually to a page since it's now much easier to use the Control Panel.

Note that if the portlet had already been added it will still be there. Also, if you want to add back the ability of adding the portlets independently you can add the following to liferay-display.xml

<category name="category.admin">
<portlet id="9" />
<portlet id="79" />
<portlet id="80" />
<portlet id="98" />
<portlet id="99" />
<portlet id="104" />
<portlet id="111" />
<portlet id="123" />
<portlet id="134" />
</category>