I’d wager that he does.
In game development, prioritizing tasks and time management are important. Smaller changes that require digging deep into the codebase are more likely to be put off in favor of more pressing tasks and bugfixes.
Further, this is his first game, programmed mostly solo during his rookie dats, so the codebase probably isn’t stellar. There’s a strong likelihood that introducing even seemingly minute changes can cause severe bugs that are troublesome to squash. I’d also bet that a lot of the time ConcernedApe spent on the 1.5 update was on squashing bugs, as that intruduced a lot of new content and changes.
Given the challenges involved, ConcernedApe has undeniably put forth pretty stellar work. There are many a AAA game that doesn’t see near this much attention post-release, and under any AAA studio, the 1.5 release would certainly be a DLC purchase.