What is relevance of "<execute-queue>" in Weblogic 10.3.0/10.3.6 configurations if 8.1 thread model

My 10.3.0 WLS config.xml has entry as below

	<execute-queue>
	<name>weblogic.kernel.Default</name>
	<thread-count>100</thread-count>
	</execute-queue>

What is the relevance of this given as per certain  Oracle documentations,thread pool configuration is automatic in Weblogic release 9 and later?

Also <use81-style-execute-queues> is not present in my configurations