According to Google communication below, starting from 15th January if you have a fallback intent with web hook enabled to process user input it could be not working, because now the user input could be intercepted by Assistant for interleaving talking. For my application is important to process even the fallback. I could just use an intent with @sys.any but it would be hard because I have several intents. Are the intents with sys.any a priority lower than the others? What happens in this case? What's the best approach?
Dear Actions on Google Developer, We are reaching out to provide more details regarding the Google Assistant Actions fallback intent behavior change that we announced on October 15, including more details on the decision and recommended steps to take with your Actions development projects. In order to provide a better experience, we now allow users to ask for some Assistant features, such as the weather or time, from within your Action. To perform this function, the Assistant detects if your Action matched a user's query with a fallback intent or NO_MATCH intent. If that is the case, and an appropriate response is available, Assistant responds to the user's request. If no response is available, or Assistant doesn't understand the query, the conversation continues within your Action. As of October 15, 2020, this new behavior applies only if the fallback does not use a webhook. Starting January 15th 2021, we'll start enabling this feature for any Dialogflow fallback intent or Actions Builder NO_MATCH intent whether or not they use a webhook. This change should not impact the operation of your Actions, unless you are using fallbacks as a way to collect input from your users. Going forward, you should only use fallback intents or NO_MATCH intents as a way to reprompt the user in the context of your Action. If you want your Actions to attempt to capture data from a wider range of user responses, create an intent that uses a Free form text type if you use Actions Builder. If you use Dialogflow, add an intent with a @sys.any type as the training phrase. We realize that this guidance for the use of fallback intents goes against some of our prior recommendations. As we continue to improve our understanding of how users interact with the platform, our approach to conversational interfaces also needs to evolve. Thanks for your continued support of the Assistant developer platform, and for your understanding as we continue to improve the Google Assistant user experience. Sincerely, The Actions on Google Team