The heart and soul of Pillars are what the writers make them out to be, hence the second game does not necessarily have to exactly mirror the first one.
Dyrwood was dark medieval fantasy, very Welsh/Celtic inspired, Deadfire is more Pirates of the Caribbean in addition to British/Spanish colonization. Doesn't mean it lacks its own dark themes, difficult choices and controversial topics. It's just different environment, arguably slightly more lighthearted and pretty, but it has its own lion's share of darkness.
For example, there is a temple on a remote island full of cannibals with sufficient gore, blood, and relative content galore. There is slavery which you can partake in if you so desire, even occasional torture. There is full-scale nudity and sexual references and innuendos everywhere. The quests and quest givers are usually very grey in terms of morals. None of the factions are good, everyone is working towards their own personal goals with the innocents below having to deal with poverty and starvation while their leaders perform power plays and squabble between each other. There is a lot of dirt behind the glimmer of the islands.
I don't really know what you are worried about. This is Obsidian, even their most light-hearted stories have enough tragedy to keep you depressed for days, and enough visuals to support it.