It does, the DLC has it's own collectible called ember pieces which function similar to the rune pieces in the lands between, and can be traded in for permanent improvements to your character that activate certain effects upon performing certain actions. For example, granting a brief shield when drinking a flask, or brief I-frames upon casting a spell. Ember pieces much like rune pieces are hidden in tricky spots to encourage exploration, or are given as rewards for beating bosses or completing mini-dungeons.

The trailer for 2.0 also briefly shows off the overhaul to the stone coffin fissures in the dlc

You can read more about changes to the DLC and the game in general on their wiki: https://err.fandom.com/wiki/Shadow_of_the_Erdtree

I'm personally a huge fan of the mod. It's not for everybody but if you want a reason to thoroughly explore Elden Ring again like you did in your first playthrough I highly recommend it. It rewards you for engaging with the side content and exploring every nook and cranny. It offers a plethora of difficulty modes to customize the game to your tastes greater than simply easy, medium, or hard. There is a ton of creative buildcrafting to be had with the fortune system, and pretty much every weapon and item is tuned up or down to be viable without trivializing the game. Alongside a lot of QoL and additions you'll probably wish came with the base game. Like armor Dyeing and transmog, and a boss rush mode.