The following is just an opinion based on the known facts regarding the new DLC. I love Anno 1800 and that there is a new season of DLCs, but honestly, I am a little bit disappointed of the newest (incoming) DLC.
It seems like they made it very easy for them to create a DLC which really just adds a new building (with new huge effects of course), but I think making these effects wasn't really a big expenditure.
I would have wished for a new monument (why isn't the new palace a monument?), that challenges me to build it – something like the court in the campaign. A new monument for the new world would have been really great.
Also, I find the effects a little bit lackluster and colorless. I would have wished for new quests, new story, new interactions, and not just a huge nice building that buffs all your stuff.
I would compare it to the Botanica DLC, that also just added a new modular building (with some of more or less good effects based on completed collections).
Of course, I look forward to playing the new DLC, but I am already a little bit disappointed with this missed opportunity. I think they just wanted to publish something okayish really quick.