I am afraid that they can ban rclone, is that possible?
I hope that no.
https://developer.amazon.com/public/apis/experience/cloud-drive/content/developer-guide
What Not To Build
We understand that developers spend a lot of time creating apps that customers love to use. We want to give you some guidelines for apps not to build on the Amazon Drive platform to save you time in building something that will not be approved during the App Review process. While this isn’t an all-inclusive list, focus your energy on developing apps that solve customer problems, which don’t violate our Terms of Use, Brand Guidelines and the App Distribution and Services Agreement.
Don’t build apps that support commercial use
Don’t build apps that harm customers or their data
Don’t build apps that make excessive requests to the API
Don’t build apps that infringe trademark, copyright or intellectual property
Don’t build apps that scrape content or allow customers to copy content from websites
Don’t build apps that promote illegal peer-to-peer file sharing
Don’t build apps that use business names and/or logos in a manner that can mislead, confuse or deceive customers (e.g., do not copy the look and feel of Amazon Drive branded apps)
Don’t build apps that confuse or mislead customers
Don’t build apps that impersonate or facilitate impersonation of others in a manner that can mislead, confuse or deceive customers
Applications that perform client-side encryption will prevent customers from viewing data in any other application, impacting the overall customer experience.