What happens when I uncheck a LinkedIn sender and publish?

Contacts enrolled on that sender who have not had a first send yet are reassigned to another sender on this flow. Enrollment stays in place. Adding a sender does not move existing enrollments. You must Publish for the change to take effect.

Contacts that already had an outbound send stay on the removed sender, unless you also select another sender that is the same LinkedIn person (login email, or a unique profile name in this workspace). In that case, in-progress conversations continue with that person and the sequence does not restart. Ended enrollments are not moved.