Hello everyone,
Until now, activity records could only be shared indirectly through a parent record like a Lead or Contact. That changes with this update. You can now share a Task, Meeting, or Call directly from the record's more options menu, the same way you'd share any other record in CRM.

2. Closed activities now shared with the parent record
When you shared a parent record along with its related list, only open activities were included. Completed tasks, past meetings, ended calls, etc. stayed out. This meant someone gaining access to a record could see what was pending, but not the history that led to it.
With the current updates, all closed activities will be shared along with the parent record, consistent with how closed deals already work.
Please note that this also applies to existing shared records like closed activities under previously shared parent records will automatically be included, with no re-sharing required.That's all for the update. Let us know your feedback in the comments below.
Thanks,
Nizamuddin
P.S. These enhancements are being rolled out for users in phases, and it's currently available for users in the JP and AU data centers.