If your question is : Does WPP expose any command line or API to publish to Wsus. Then the answer is no.
if it's : Does Wsus expose API to publish. Then the answer is yes. That is the API that WPP use to publish these updates.
See : Local Publishing
and : Wsus 3.0 Class Library Reference
if it's : Does Wsus expose API to publish. Then the answer is yes. That is the API that WPP use to publish these updates.
See : Local Publishing
and : Wsus 3.0 Class Library Reference