Update: EA rewrote the blog post that contained outdated information to say that Grand Operations will be available at launch. The original story is therefore outdated.
Original story: EA has released a refresher on Battlefield 5's multiplayer modes (fix: released last month, not recently), starting with its replacement of BF1
The other mode that will not be available at launch is the Battle Royale mode, which only got a moment of stage time on the E3. I would expect it to be a decent wait (especially since DICE did not even have a logo to show), but Grand Operations was already playing at preview events, so I bet that "short" really means short in this case , I speculate, but DICE will probably issue it at some point after the initial start-up hurry, give or take whatever time is needed to smooth problems.
I like the operations and Grand Operations modes in principle, but I'm always more I'm looking forward to playing a regular old conquest when a new battleground starts. I found BF1's version of Conquest flawed for a couple of reasons, so I am glad that BF5 has scrapped the Colossus and the new rating system in favor of classic rules.
For more on this thought, here are some of the improvements we've seen in BF1 in the first Battlefield 5 Alpha. There will be an open beta in September so you can try it yourself. Battlefield 5 will launch on October 19th, or about a week earlier, if you're a member of Origin Access.