Our whole sales teams operates out of Tasks so this is often critical that we reassign tasks. I found a HubSpot integration that works great for us - Task Maestro. (I have no affiliation with them) I put this into a workflow and either manually enroll contacts from a list or send them to the workflow from another workflow. It works great.
I am a little worried about when I have multiple tasks from different people, but for now, it reassigns tasks to the new Contact Owner.
