Microsoft has moved retention processing for SharePoint Online, OneDrive for Business, Teams, and Yammer from the Managed Folder Assistant to a new retention assistant. (background processing job). It’s part of an effort to use workload-agnostic processing whenever possible to perform retention actions across Microsoft 365.
The Exchange Online Managed Folder Assistant (MFA) runs in the background on a workcycle basis to make sure that mailboxes are processed at least once a week. Most of the processing involves mailbox and Office 365 retention policies and runs smoothly, but how do you know what MFA has done?
A question asks how to remove a bunch of emails from a shared mailbox. You can use OWA to do the job, especially with its Cleanup Mailbox option, but perhaps some administrative action is needed.