DFDS have announced a 6x weekly Rosslare to Dunkerque (France) route launching on 2 January 2021. Three roro ships have been chartered for the route. The initial target is only freight/trucks, but it may be marketed to cars in the future.
https://www.dfds.com/en/about/media/news/dfds-opens-direct-ireland-france-ferry-route
Quite some competition for Irish Ferries and Stena. I assume the long crossing time (22-24 hours) makes it unsuitable for live exports (a substantial's contribution to Stena's operation).