@Lorenzo Jorquera You could leverage Microsoft Graph Change Notifications instead with any service that supports a HTTP Endpoint (like a Logic App, an Azure Function, etc.). There is an additional doc that talks about change notifications for Microsoft Teams that you could refer to as well.
So, for each channel you would have to create a subscription that listens to new messages in the channel and triggers your Logic App (or any endpoint you need), which would take the data from the notification like channel details to categorize the videos.