CNN chief prescribes calm after staff anxiety over Paramount’s expected purchase of parent company

Word had barely spread about Paramount’s apparent victory in the competition to buy Warner Bros. Discovery before CNN chief Mark Thompson wrote to staff members. His message, in effect: Keep calm and carry on.

It’s a tall order. The network’s future — whether familiar faces stay or go, whether the outlet changes editorial direction — will be watched intently if the corporate deal clears regulatory hurdles and goes through. Anxious observers are left to interpret signals from Paramount’s...