Amazon is rolling out a new feature "Answer Update"

The new feature in Amazon Alexa will notify users when the voice assistant learns the answer to questions it didn't previously know.
The idea is to allow people to better take advantage of Alexa’s quickly improving Knowledge Graph.

Usually, when Alexa doesn't know the answer to a question, it replies with statements such as "I don't know, but I am always learning". However, with the new Answer Update feature, Alexa will be able to answer those questions when it finally figures them out.

In order to activate the service, you need to say "Alexa, enable Answer Updates". Saying "Alexa, turn off Answer Updates" disable it.
https://voicebot.ai/2018/08/06/amazon-alexa-testing-answer-updates-feature-that-will-notify-users-when-it-learns-a-new-answer/