While I never watched the Hidden Block guys much, I know that the Normal Boots guys kind of drifted apart. Some of them were always business partners more than friends, and some of them turned out to not be great people. A lot of them have had controversies since the game came out. Additionally, once their channels got bigger, there wasn't really a need for the Normal Boots umbrella anymore - from my understanding they were all mostly operating independently.
I think the developers haven't made more games like this because - given that one of them is married to PBG - they probably weren't ever planning to make games long term. This was a fun project to work on, but not the start of something for both of them. For what it's worth, Illus Seed, the game dev thing run by Cara Hillstock, has made another game. It doesn't seem to be in the same genre. It's called "To Be With You", and it seems to be a more serious and non-anime-themed look at rough relationships. Check it out and see if it's for you, but know that it's got a completely different tone.