[quote]From August 21st after doing the cross save, will I be able to play immediately on Battle.net or will I have to wait for October on Steam? Also if I do the reverse (from PC to PS4) can I play immediately on PS4?[/quote] PC move https://www.bungie.net/7/en/PCMove Cross save https://www.bungie.net/7/en/CrossSave More info will be given closer to October. If you choose to activate cross-save with D2 you will have the ability to choose from one of your PLATFORM saves so that it can be used on all platforms moving forward. For example: Xbox has characters 1/2/3 PSN has characters 4/5/6 PC/BNet/Steam has characters 7/8/9 And you choose the PSN characters then it becomes Xbox has characters 4/5/6 PSN has characters 4/5/6 PC/BNet/Steam had characters 4/5/6 You won't be able to access characters 1/2/3 and 7/8/9 when Cross-Save is active. In order to access characters 1/2/3 and 7/8/9 cross-save needs to be disabled (assuming it can be toggled off and on). If you have D2 content on one platform that's not purchased on another then that doesn't suddenly mean you gain the licenses for those DLC when Cross-Save is active. You still need to purchase the corresponding content for each connected platform in order to access that expansion’s content. Only the base game, Curse of Osiris DLC and Warmind DLC is free-to-play for all platforms this coming September. You need to Buy Forsaken+Forsaken Annual Pass and Shadowkeep for each platform. Cross Save will preserve all gear, character, and items across all platforms regardless of expansion ownership.

As long as you own licenses for the content you are playing on the platforms you want to play on, you can play immediately. I suggest you read up on it a bit https://www.bungie.net/7/en/crosssave