Updated April 15, 2024: We have updated the rollout timeline below. Thank you for your patience.
This feature will enable Teams users to delete/remove items from activity feed.
This message is associated with Microsoft 365 Roadmap ID 181794
The Remove functionality can be found under the ellipsis menu in the activity feed:

After an activity feed item is removed, the user is informed through a toast notification:
When this will happen:
Targeted Release: We will begin rolling out mid-December 2023 and expect to complete by mid-February 2024 (previously late January).
Worldwide, GCC, GCC High & DoD: We will begin rolling out mid-February 2024 and expect to complete by late April 2024 (previously mid-March).
How this will affect your organization:
There are no tenant level settings. Defaults will not change.
What you need to do to prepare:
You may want to notify your users about this change and update any relevant documentation as appropriate.