The authors named the reason for everything as - we RAN OUT OF ROOMS for content, which I consider a CHEAP excuse (excuse) because, guys, YOU have a whole CASTLE -_- what's stopping you from making tabs and rooms in it, like you did with the lab and the maid's room?
If you're talking about their official response in the official Steam-Forum than i feel like you're misunderstanding something:
"We don't plan to make a second DLC. There really isn't much room to continue the story beyond the base game and If we kept adding more to the existing story, it would make it less and less coherent."
That's figure of speech, not meant in the literal sense about technicality. And tbh i can kinda see that, the DLC's featured some areas which felt a bit loose in the basegame, to give it a more finishing touch, the areas which they could explore would either involving adding entirely new plots or as a continuation.
and there will be a new one with pirates (I didn’t really like it because the characters are kind of strange).
That's one thing i'd agree with you... i mean i might still check it out, esp. here (to test it) maybe there is something which hooks me in. BUT overall i also don't like the character-design that much... i foun CIC for the most part pretty great and clockwork (which seemingly get the remake you mentioned).
And if we are going to nitpick, then the DLC with the GYPSY reveals and DESTROYS the entire content and the entire plot, in essence, because (this is a spoiler!!!) we get into the world (of Lovecraft -_-) where the main EVIL is located and with her help we defeat it, i.e. (logically) the spell and so on should disappear,
If i get the direction right you're hinting, than i'm also not sure if you're correct on this either. Maybe i really need to replay this specific scene again, to check the phrasing/wording again. But i'm pretty sure that the "gypsy" called him some sort of the gatekeeper and not the actually 'main guy' as you put it. And at the end she also mention that she keeps hunting them, so i did assume it's not the "mainguy" but just one of his stronger soldiers. I mean Lovecrafts (to my knowledge) not only had one of these voidgods but multiple like Cuthullu and Cthylla, so the person you thinking of might not vanish because she was connected with someone else.
This will not be significant content, I would not count on much (plot). 1n 100% = these are costumes for new characters (Halloween) and nothing more. What prevented them from releasing them right away is unclear.
I honestly don't think it's just costumes. esp. due they specifically mention the basegame characters which already have them, i'd expect some new scenes, but surely not as expansive like another DLC sized content expansion. And well they mentioned why in the qoute, because the stuff isn't finished yet and would've delayed the DLC another 2-3 months (which is another reason why i don't think it's just costumes).
I mean look, i get part of the frustration, i was also slightly disappointed when i read there won't be another expansive DLC or something in the direction. As you i don't really about their next game, and CIC with it's atmosphere / lore & Story did resonate very well with me. It's always sad when the especially good ones come to an end. But the Game costs ~10 Bucks, and the dlc another ~5 Bucks. And !!! in my opinion !!! we ate good and got quite of our moneys worth back. It might not have the content-bloat as other Games you find here, but i'd argue you rarely find Games with that level of quality. And also the whole way how this Game is build i'd argue is rather unique, esp. in context of a smut game. The closest resemblences which i've had, if it comes down to stuff like the overall art,- and animation-direction, the way how puzzles work, atmosphere and ui design... it reminds me more of an Hidden Object Game, then any other porn game i know. (And surprisingly enough i mean that in a good sense). My disappointment doesn't come from feeling i was ripped off or they didn't deliever, but rather the opposite, because they delievered, i'd wish we just got more of it. But well...