To all the commenters so far,
This wasn't axed. The author just prefers to write shorter stories. And would you rather have 25 chapters with high quality art and story, or one or two hundred chapters filled with filler and lazy excuses to stretch the chapter count?
Is the chapter numbered incorrectly, or was that done by the author? I feel like it should be changed to 4.2, since X.5 normally means a bonus, and some people might skip this chapter thinking that's all it is.