When used outside of RS exercises, there is a need for some indication that the conclusion is not just random paragraphs of text. It doesn't need to be the current treatment, but as of right now, that is the presentation.
But yes, that presentation inside a RS exercise box doesn't work well. It would be easy enough to quash the styling on a conclusion in that context. (There are also some other issues, like an overly large top margin, that are coming from presentations designed for other contexts being used inside that one). I'm happy to PR that.
But my first thoughts are in line with Chrissy's. A conclusion doesn't seem like it should be presented as the reader is working on the first task.
In a static presentation, that content will appear once at the end, after all the tasks. In this presentation, it feels more like a "bottom statement" than a conclusion. It is tempting to put notes or hints or other content that applies to all tasks - a decision that won't make sense in other renderings.