To me, the very line you suggested needs removed tells me this was never meant to be incest based.
I'm not going to go too deep into this, already had plenty go into "attack mode" about this topic, but I'll respond.
The way patreon is, I wouldn't mention anything that is a bannable offense by them. There is zero reason to even hint at something they don't like when they control your income. Any dev that uses their site for funding would be be ill advised to mention anything that would jeopardize their income, it would be completely foolish. They've booted more than one person from their site for things said off their site.
The line I was referring to is basically just a passing thought in the game during the setup, mentioned once, then forgotten. The character could come in later, but I'm not betting on it. There are little nuggets in the game which led me to have my beliefs, others don't see it, but I do. The normal "landlady" trope is just replaced with another word to me, new spin on an old tale. You say removing "lines to suit a fetish a" seems forced, to me, adding a throwaway line to deflect from "fetish a" screams "avoid the ban hammer". All it takes is one person to hound patreon to dig deeper and all the funding could be locked up, or lost, while they do an extensive rewrite to suit patreon. This happened not too long ago to a dev I help from time-to-time, cost him a month of productivity to make them happy, then having to work on a patch on top of the normal development, just slows you down more. The game is just skirting a fine line to me, enough of a hint to make cest fans happy, and the explicit mention to make the non fans happy. No patch needed, so less work in the end.
As far as this:
There may be an implication you are seeing, that is actually there, but that was never intended
They made the game, how could it not be intended. Like I said, some see it, some don't. I'm sure all the devs who make lolli games assert all the characters are 18 too, because that is what they intended, let's just believe them. I'm not trying to besmirch anyone's character, but don't piss on my shoes and tell me it's raining.
I'm sure if you ask the devs of numerous games that are funded on that site if there is any cest, 90% of them or more would deny it, and that is the smart thing to do. I'm sure Luxee vehemently denies he has anything do do with the patch for Apartment 69, the appropriate response would be, "I don't know, that must be a fan patch". Why make yourself a target.
The story is good, not saying it isn't, all this discussion is just semantics. People see what they want to see, you won't change 95% or more of anyone's mind nowadays. There is no discussion, only opinions, I'm right, you're wrong.
This is just a dumpster fire of a topic anyway, I regret even making a comment in good faith to you in the first place, it just started the dogpile from others, even the writer, any response will be "the dev said it doesn't have it in the game", the dev whose income is reliant on obeying rules from a payment distributing site that explicitly forbids said content.