There's no default retention policy, so generally they will not be removed. An Office 365 admin however can always configure a retention policy that will affect this though, and there's nothing you can do to avoid it.
Is Retention period applicable when using Microsoft Graph API
I am a developer and I have a backup application that compresses data from a user's machine and stores it onto his Onedrive on the Cloud using Microsoft Graph API. My users have either E3 licenses/M365/O365 licenses etc.
I wanted to know if the files that my application has compressed and copied onto your cloud will be deleted internally due to the Retention Policy ?