Okta doesn't perform DELETE operations on User objects in your SCIM application.

[anishsinha]

Could you please suggest which event will trigger if a user is de-assign from respective application.

public delegate Result getUsers(int startIndex, int count); or getUsers does not get triggered.

[FabianZoon]

The fun of a 0.1 version project, is more a proof of concept.
First of all, don't forget to enable the Deactivate Users in the Provisioning in Okta. (I guess that is your problem)
That should trigger an user update when it is deactivated (more info you can read on https://developer.okta.com/docs/reference/scim/scim-20/#delete-users)