Amazon Alexa doesn't always know the answers to your questions. Since that can be pretty frustrating, Amazon is rolling out a new feature that'll notify you if Alexa ever figures out the answer.
The new feature is called Answer Update, and it'll alert you when an answer to your question has been learned. Usually, when Alexa doesn't know the answer, the response will be something like "Sorry, I can't find the answer." Now when Alexa is stumped, it'll reply with "If you ask me a question and I don't know the answer but I find out later, I'll notify you." You can turn on the feature by asking Alexa to "turn on the Answer Update feature."
Having your questions finally answered might be nice, but chances are, you either looked up the answer elsewhere, or you completely forgot you ever asked the question. So, perhaps an answer alert so far down the road might be somewhat annoying? We'll have to wait and see.