Can chatbots like [Rasa] learn from the trusted user - new additional employees, product ids, product categories or properties - or unlearn when these entities are no longer current ? Or do I have to go through formal data collection, training sessions, testing (confidence rates > given ratio), before the new version be made operational.
Many Chatbots do not have such a function. Except avanced ones like Alexa, with the keyword "Remember" available 2017 +/-. The user wants Alexa to commit to memory certain facts.
IMHO such a feature is a mark of "intelligence". It is not trivial to implement in ML systems where coefficients in their neural network models are updated by back-propagation after passing learning examples. Rule-based systems (such as CHAT80 a QA system on geography) store their knowledge in relations that can be updated more transparently.