Have you not looked into the Steam store page and all the different editions they are offering? They've probably changed things a bit, but when they first announced the game, WB said in order to get the full story, you'd have to buy the Gold Edition which costs $100. They said the Silver and Standard editions both have their own conclusions to the story, but they aren't the entire story. So they basically hid part of the game behind a day-one paywall. I noticed they took the information off Steam regarding the different editions or if it's still there I can't find it at the moment.
Then there's the fact they are reusing the same animations, dialogue and voice acting (not actor, same lines), same soundtrack with a few new songs, etc. There's also some talk about your fortress upgrades being locked behind micro-transactions (or certain tiers unlock with Silver/Gold editions). Monolith aren't saying much when people ask about the paywalls, but it has been a while since I last looked into it and they may have made some statements since then. The release date is still set in October, so there's still plenty of time for them to make changes before the game is launched.
All-in-all, I wasn't impressed and I was pretty irritated when I read the statements from WB about the paywalls and micro-transactions. I know they got a lot of hate right off the bat, so we should be hopeful that things aren't as bad as they seemed.