Whereas most FromSoftware received two DLCs, Elden Ring will only get Shadow of the Erdtree, FromSoftware president and Game Director Hidetaka Miyazaki confirmed to the Chinese website Campfire Camp, thus effectively denying previous rumors of a second expansion slated for 2025.
It is the first and last DLC. We have no plans to add more content to Elden Ring. [...] FromSoftware's style of doing things is that it generally does not allow the future of an IP to be easily locked, so it is better to leave some possibilities.
But as far as "Shadow of the Erdtree" is concerned, it is the only DLC. Related Story Stellar Blade Review – Nearly Automatic AngelMiyazaki also explained why that is the case: Elden Ring emphasizes the exploration and adventure of the big world.
In order to provide such an experience, a vast and huge scene is inevitably needed. Therefore, instead of splitting it into several parts, it is better to simply make one big.
If they were sold separately, the freedom of exploration and sense of adventure would be reduced. It took FromSoftware over two years to make Shadow of the Erdtree, so the DLC must be meaty indeed.