There are many more examples that blur the line between "uncensored," "restored," "R18+," or "extended" content. Often, modders introduce new material that may go beyond what the developers ever planned or coded. Yet, it’s still often labeled as “uncensored”—which is why the term is so debatable.
The Halo example I pulled out of my ass. Though, the TV series AFAIK, would been somewhat apt way to say very bluntly that a game is the game, and an anime of the same franchise is the anime. Just because other types of media are the way they are is not grounds to say the game "should" have been anything else but released. They're separate. Same logic in reverse would also apply to something like "Action Taimanin" where rest of that series' games have, to put it lightly, hardcore sex scenes that "Should be part of this game too" but that was not the goal of end product. And nobody calls their R18 nude mods for that uncensored. Only results of "Action Taimanin Uncensor" I can find, are talking about the type of uncensor I talk about. Surprising even me, but that is how universal understanding I have is.
I also have to say I am extremely skeptical that porn sex scene hentai games would get anything but AO rating, when it comes to US. I assume the games with M rating are ones without their R18 content.
Your own examples of these mods somewhat defeat your own point? Hot Coffee is "Hot Coffee", not "uncensored". "PC Mods" instead of "Uncensored" Unrated and uncut are close enough to not be discounted in same way. But additionally, these two mods are even with 3rd party content, are in spirit of described goal of the mods and content you expect in games like Manhunt or Agony. Extreme violent content is already on table with those games. Extreme violent content is what these mods add.
Meanwhile, when speaking about Senran Kagura games and walking through my personal logic; I am not expecting any extreme content from SK. I, from passing interest in Senran games expect a Senran game to be risque with certain limits. No full nudity. I like some stuff exactly that way. Also from the contextual sense, reading "Senran Kagura X Uncensored" my first assumption was "Oh, it was censored somehow when localized? Well, that makes sense, I wonder what they exactly censored?" only to be flash banged by a pretty big "wait what?". Given the context of something like Senran Kagura, most people would assume first that "uncensored" would mean that the game was censored during localization and if you seen Senran, you'd think "Well duh, of course it was". If I had not looked at screenshots and description, I would have likely just downloaded the mod with that face value and been unpleasantly surprised. Most fans of Senran Kagura and such games, know and assume what it is and is not. Most fans of Japanese console video games "know" what an uncensor of a such game would most likely be. In context of this, or Bhikhuni, that understanding is betrayed. We know a playstation or nintendo platform game does not have full nudity ever. Most of us do not read interviews and personal life goals of developers. Most of us take the game as it was made and not "what it was supposed to be". Most of us, most definitely, do not take some fan's rewrite as gospel. Some fan's rewrite is not uncensoring. Some fan's rewrite is some fan's rewrite.
For past decade, for 3DS and so on, most simple "Uncensored mods" are just swapping assets back and forth with the localization changes.
Bravely Default,
Bravely Second uncensor restores bunny girl and other outfits from Japan release,
and nothing else.
Project Zero: Maiden of Black Water, where uncensor is used to refer to content changed or removed during localization from Wii U Japan version to west, and subsequent releases such as Steam
and nothing else.
Tokyo Mirage Sessions #FE for Wii U has an "Restored" patch some refer to as an uncensor that changes bikini outfits and posters changed during localization back to original,
and nothing else.
Xenoblade X DE - Uncensored and Retranslated is a patch that does what it says. We know it is not saying "skidaddle skidoodle, every female's a nood".
This also shows, it is "
Sometimes modders introduce new material", not "often". And even in my example, that is a retranslation, a cousin to uncensor, but arguably more "modder's own handiwork" than usual simple content uncensor. Uncensor is more than less as understood term like "undub" is, another even more distant cousin to a content uncensor.
General confusion to this patch naming sense seems to be roped in with sexually explicit visual novels becoming more popular. It seems it's popular to call content restoration of these releases "uncensor". Makes sense for most visual novels where sexual content is intended full experience but is cut in some releases such as steam and consoles. For steam developers have offered "R18 content" as DLC after easing of adult content policy or "R18 patch" being offered outside of Steam. These cases have passable reasoning for use of the term.
But, it does not make sense for Senran Kagura or Bhikhuni. For these it is not restoration of content, but changing and adding 3rd party made content. Changing and adding of content is what every Oblivion adult mod is as well. Yet nobody calls sexed up Oblivion a restoration or uncensor, even if you did find a Todd Howard in an interview saying he would have loved to do that himself but put that energy into horse armor instead.
In the end and semi TL;DR: Your claim "there is no generally agreed, general understanding what uncensor even means" is just wrong. The vast majority of hits you get from searching uncensor patches are in framework I've talked about. We have a general understanding and even at it's best, this patch for this game does not fulfill that understanding and is likely mislabeled due to confusion with "uncensor" R18 content patches for sexually explicit adult games, which Senran Kagura is not. When I googled for this response, I got no hits to support your reasoning. The Adult Game scene is
the source for muddying these waters. For many R18 visual novels, "uncensor" is passable term (at best), and officially "R18 something" DLC/patch. The game of broken telephone with this term through this sub-community has ended up in a fan rewrite posing as restoration being called an undoing of censorship.