HI! We have a tiny hotfix today for users who have been experiencing the issue causing old save files to make the campaign levels not show up.

If you're still experiencing the bug after restarting your computer and verifying the integrity of the game-files please email support@landfall.se

As for new content updates, it's looking like they're coming in February - you can read more about what's to come in February-April here:
https://steamcommunity.com/gid/103582791455606666/announcements/detail/1703981547423952931