Rebellion's just announced a mini-campaign for Sniper Elite 4.
Deathstorm Part 1: Inception comes out on 21st March on PC, PlayStation 4 and Xbox One. It's the opening chapter and mission in a three-part campaign, playable from start to finish for one or two players. It's set after the events of the main game, with the first chapter taking place in the colder terrain of northern Italy. There, a Nazi naval base was recently the target of a bombing run.
Here's the official blurb: