The simple answer is that yes, Borderlands 3 will be making the jump to next-generation consoles. Developer Gearbox Software and publisher 2K Games made the announcement during PAX Online, also announcing a few additions to both current and future versions. The PlayStation 5 and Xbox Series X are getting their own versions of the game, with the current versions also getting some love.
The next-generation version features will include three and four-player split-screen by default. There will also be an option for Borderlands 3 for free to current-gen owners who will transition to the next-gen consoles. As for gameplay content, everything in the current version will be brought over to the next-gen ports. All of your DLC will be moved over when you update to the new version. That means that all of the DLC you have on the current game will not be lost.
So yes, no paid upgrade here, so at least 2K isn’t making you double-dip for the game.
The game will have support for some unique features with the next-gen port, like improved resolution. 4K resolution and 60 FPS in single-player mode will be unique to the Xbox Series X, as the Xbox Series S cannot support those modes in any stretch.
Additionally, there will be two-player vertical split-screen coming to both current-gen and next-gen editions.