+1 for new stories. Adjusting the existing content is great and all, but frankly it makes no difference if we have no desire to continue playing because we're bored to tears with the story. I'm sure a lot of people have identified some imbalances here and there, or are unsatisfied with the lack of this or that, but RPG's are first and foremost story driven content...and you can only go through a story so many times before you can't stomach it anymore. Having access to new companions isn't going to provide sufficient new content to alleviate the tedium of playing through the entire story for a fifth or tenth time.
Pretty much the only reason I still have the game installed at this point is that I'm finishing a playthrough with my wife on split screen. After that I'm done with this game until there's a new adventure...something completely new and preferably unrelated to the illithid storyline. I'd LOVE it if they started doing some classic D&D content like Tomb of Annihilation or Curse of Strahd, or even just a couple of the starter adventures like Lost Mine of Phandelver. Or as I said in a separate post they could do faithful reproductions of older games like Neverwinter Nights and the other older Forgotten Realms games.
Either way, little tweaks here and there won't be enough to keep many of us playing much longer. The game is good enough as it is, and I'm already hungry for a new adventure.
Neverwinter nights and Icewind Dale as much as it would be nice to see the later also added to the game have there own IP's to the game franchise and Larian would need a secondary license to create that in the game. The Neverwinter IP is currently owned by another company perfect world entertainment and is run as a more world of warcraft style mmo with a lack of choice in design. So as long as perfect world entertainment owns the IP that will not happen with Neverwinter. It is basically completely off the table. I know a large number of people have mentioned Neverwinter because of Neverwinter Nights but when the IP is owned by another company WoTc cant just give them the IP without violating the contract with the existing company so there is no possibility of that happening for as long as Perfect world has the IP on that game. Its also unlikely that WoTc would give them the Icewind Dale IP without a huge payout. Adventure packs are not off the table but your more likely to see them expand content with existing content that was pulled back or removed. I highly expect they would adapt the Artificer Class as well to a DLC as its one of the most requested additions to the game. DLC would most likely contain existing content. A complete new adventure with new companions ect would be a different game not a DLC. But additional adventure packs is possible you would just end up playing the campaign with existing assets and as an addition to the story. There would most likely be new companions introduced with there own tags into the story as is the bench mark for CRPGs but it would be in addition to existing content rather than removing it. Commenting on not altering the existing ending that is unlikely it would most likely add some ending changes. I could also see the ending removed moved back or altered with level extensions. Should they want to extend the game with act 4 to include the upper city some of these things are just practical and make a ton of sense. Because not doing it just does not make sense to any crpg. Its never been done because it retracts from the existing game and is instead its own game.
Often what you might expect is a side adventure in a specific act as its own act with its own story line that plays along side the existing act.
Waterdeep Dragon heist could be an expansion to act 1 or lost mines of Phandelver as 1 act mini adventures Dragons of Icespire peak is another small adventure that could be worked into act 1. They could be a second hag added to act 2 as its own adventure and a return of auntie ethal and a third hag to act 3 possibly leading to a confrontation with the hag coven, the later and more custom adventures from larian makes more sense to expand without taking away from the existing game however. More options to move around the acts may exist as well or expansions to new locations around the sword coast. Waterdeep dragon Heist is a possibility with Gale being in the party.