Hi PubSub sends last published items at user connection, and when subscribing to a node. Updating capabilities does not affects pubsub subscriptions.
So, updating capabilities enable or disable PEP events you may receive by implicit or explicit subscription. But i don't think you should get the last published item in that case. Caps are just kind of filter. By the way, when clients enables a new capabilities, it can also ask pubsub for last published items on related nodes.
