https://www.pcgamer.com/battlefield-5s-grand-operations-mode-will-come-shortly-after-launch/

Today, EA posted a refresher on Battlefield 5's multiplayer modes, beginning with its replacement for BF1's multi-match Operations mode. Grand Operations will see teams battle over multiple in-game 'days' through different modes including Airborne (one team jumps out of planes) and the respawnless Final Stand. But not right away. According to the post, Grand Operations is coming 'shortly after launch.'

The other mode that won't be available at launch is the battle royale mode, which got just a moment of stage time at E3. I would expect there to be a decent wait for that one (especially given that DICE didn't even have a logo to show), but Grand Operations has already been played at preview events, so I'd wager that 'shortly' really means shortly in this case. I'm speculating, but DICE will probably roll it out sometime after the initial launch rush, give or take any time required to smooth out issues.