I've implemented generation of push notification on account removal. This is now supported by unencrypted and encrypted push notifications.

In case of plain notification, server will add element

<event xmlns='http://tigase.org/protocol/account#event' name='account-removed'/>

to the notification sent to push component that will handle forwarding this information, see tigase/_server/tigase-push#58

In case of encrypted notification, server will set type property of the encrypted payload to account-removed. Support for this needs to be added and properly handled in the XMPP client receiving this notification.

Enabling this feature is done by setting send-account-removal-notification property of urn:xmpp:push:0 SessionManager processor, ie.

'sess-man' {
    'urn:xmpp:push:0' () {
        'send-account-removal-notification' = true
    }
}