Um where are the mods that shown in youtube videos or trailers? Zombie, redlight green light e.g.External link →
They are often created and discussed over on the /r/BattlefieldPortal sub, as well as via whichever platform that the Experience creator themselves choose to use to share it to the community.
There's also a pretty swanky Experience Browser on BFPrime, love the work that those folks have put into that.
And while I cannot share definitives on when they will be, you can expect "Redlight Greenlight" and "Zombie" style modes as Featured Experiences in the coming weeks too!