So a site accidentally broke the embargo for the redacted mode.
TL;DR:
Seperate mode developed by Ripple Effect (formerly DICE LA):
Will feature two maps each from 1942, Bad Company 2, and Battlefield 3 at launch + 2042 maps. All remastered or rebuilt in Frostbite.
Includes weapons, gadgets, vehicles, modes (e.g Rush) and teams from all three games.
You can mix and match teams in any map.
Includes what sounds like the visual scripting editor DICE has shown before (in devs note for previous games and what not) that they use to make rulesets for game modes. Allows for simple rebalancing or making full new game modes.
Will be added to after launch. (I imagine they probably plan to at least add a couple maps from BF4 and BF1 at the least, and they'll see from there).
Article: 
Battlefield Portal is a highly customizable and community-driven experience created by Ripple Effect Studios. Through this mode, players can not only build and share their own custom game modes, but all players will also be able to browse and play these modes right from the game. The main Portal menu will have three options, one for DICE-created experiences, a second for Community-generated modes curated by DICE which rotate periodically, and then the editor itself.
Ripple Effect Studios General Manager Christian Grass confirmed that in addition to all of the Battlefield 2042 content being available, Portal includes content from three classic games in the franchise: Battlefield 1942, Battlefield Bad Company 2, and Battlefield 3. Along with specific weapons, vehicles, and gadgets, Portal brings back six classic Battlefield maps, available to use in these custom matches. The list includes Caspian Border and Noshahr Canals from Battlefield 3, Battle of the Bulge and El Alamein from Battlefield 1942, and Arica Harbor and Valparaiso from Bad Company 2.Better yet, all assets from these maps have been rebuilt from the ground up in the Frostbite engine and reimagined for modern technology. The map layouts themselves remain as close as possible to how fans remember them, but for the older maps from Battlefield 1942, destruction physics have been added.When building content in the Portal editor, players have unprecedented control. Senior Design Director Justin Wiebe provided an early look at the process. Starting off, players select the game mode they want to center their experience around and this includes modes like Rush which isn't featured in the main Battlefield 2042 game. In addition, players have the option to center each team on a specific Battlefield game, meaning WW2 soldiers can go up against the new Battlefield 2042 specialists if the player wants. However, teams themselves can't be mismatched with different era soldiers.
Weapons, gadgets, and vehicles can also be customized, letting players dictate which ones are available by enabling or disabling over 100 options. One thing Wiebe made clear is that weapons and vehicles won't be balanced, so naturally, WW2-style content may not be as effective when going up against futuristic tech from Battlefield 2042. However, players have plenty of options for adding their own balance to the game mode by customizing settings like increasing the damage on WW2 weapons or giving more players to the 1942 team.These more granular details are added is through the final piece of Portal, the Rules Editor. This is likely going to be a little intimidating for those not familiar with programming, as it utilizes a very impressive visual scripting editor, allowing users to input their own logic and custom rules. During the demo, Wiebe added logic that healed players after earning a kill as well as swapping the team's weapons in a Gun Game style mode. While the programming may seem overwhelming at first, Grass did confirm that the studio would be producing tutorial-style content and videos to help get all players up to speed if they want.
In addition to publishing their experiences, players can even share the custom logic they've created with the community. From a development perspective, this could really help those who are stuck at a certain part, overcome some hurdle, or perhaps those wanting to develop a game mode with a group. Better yet, every time a change is made to the logic file, the original version isn't overwritten. Instead, it is saved as a new file to be shared, making sure the original version is left untouched.
Grass finished up by revealing that Battlefield Portal will be included in the live-service plans after launch. Content will continue to be added over time and as new content comes to the main Battlefield 2042, it will be available in Portal as well. Most importantly, DICE plans to keep a close eye on community feedback to help shape the future of Portal. If the community feels strongly enough about something, like adding even more content from other Battlefield games, the studio will likely consider it.All in all, the lifespan of Battlefield 2042 appears nearly infinite thanks to this major community feature. While Battlefield 2042 won't have a Battle Royale at launch, perhaps some aspiring player will go ahead and create something along those lines using Portal. At this point, only imagination is the limit.Now all that's left is for EA and DICE to reveal the game's last mysterious mode known as Hazard Zone. According to members of the development team, this mode will be revealed closer to launch, though they teased that it's quite different from the All-Out War side of the Battlefield 2042 experience. Instead of massive maps with tons of players on each side, Hazard Zone places a focus on tight, squad-based action. Unfortunately, no more was said about the game mode but with only a couple of months left before launch, players won't have to wait too much longer for answers.
TL;DR:
Seperate mode developed by Ripple Effect (formerly DICE LA):
Will feature two maps each from 1942, Bad Company 2, and Battlefield 3 at launch + 2042 maps. All remastered or rebuilt in Frostbite.
Includes weapons, gadgets, vehicles, modes (e.g Rush) and teams from all three games.
You can mix and match teams in any map.
Includes what sounds like the visual scripting editor DICE has shown before (in devs note for previous games and what not) that they use to make rulesets for game modes. Allows for simple rebalancing or making full new game modes.
Will be added to after launch. (I imagine they probably plan to at least add a couple maps from BF4 and BF1 at the least, and they'll see from there).
