Like, where was it going to go from here? The president is dead, Komacchi's deal is in the open and being dealt with. The plot has been wrapped up and the themes were pretty strongly communicated in the end. This is a bit abrupt, but, like, if it continued, it had, like, one or two additional chapters in it before it just fizzled out.
And we're getting a couple of additional chapters anyway with the two extras, so, like, we can see more of where they're at now.