Not confirmed yet, but quite likely
The Legend of Zelda: Breath of the Wild saw expansion through some downloadable content, which probably means Tears of the Kingdom will as well. Nintendo hasn’t confirmed that just yet, but the official website for the game may have let loose with a confirmation already.
The official website for The Legend of Zelda: Tears of the Kingdom includes a bit of text towards the bottom that certainly seems like it’s confirming DLC for the game. In particular, the fine print has a section marked by two asterisks that states “full version of game required to use DLC.” The asterisks denote a section in the site above where DLC is discussed…or at least it should. This is where the problem comes up.
While other portions of the site are indeed marked with asterisks that are explained in the fine print, you can’t find any blurb that includes two asterisks. That means either the fine print is a flat-out mistake, or Nintendo accidentally shared this fine print before they meant to. It honestly could be either situation, and the correct one is left up to speculation for now.
Again, it’s incredibly likely Tears of the Kingdom will get DLC and this blurb is the closest confirmation we have of that yet, but nothing is official at this time.