I've said it before, but I'll say it again, the Rick and Morty writers have definitely been looking at the "rule 34" stuff, AND I'd put a small wager on them having seen this VN too.
Incest baby IS canon ...
Yeah, there is no way the show staff isn't aware of the porn (and the theme in a lot of that porn (incest)) around the show. I doubt very much they are actively seeking it out. Looking at fan created stuff (even porn) while working on a show is highly discouraged. As to this specific game, I very much doubt anyone on the staff knows or cares about the Ren'py version (and I'm very happy to keep it that way). Ferdafs game is pretty big though, and pops up in some normal google searches, so that's much more likely to have been spotted.
It's not the first time we've had incest in the show, it gets inserted a lot (that's what she said). Although, it's the first time (and hopefully not the last time) between main characters. Also, not the first time we've had cannibals and incest paired together too... weird...
Sadly Morty and Summer skipped the fun part of the incest baby, but I'm guessing this concept was already well over the comfort line for a lot of people (even in the porn community people don't like incest). I'm personally hoping it inspires a lot more Morty/Summer porn/comics. New ones have been lacking for a while and it's a lot harder to get my fix from this game now that I'm working on it.
I think part of the reason incest is such a large part of the porn side of the fan base is a lack of pairing options for Morty. The only main stay female characters in the show are Jessica, Beth, and Summer. We the audience, and Morty the character, know almost nothing about Jessica, which makes it hard to see her as much more than a sex object. And yeah, Morty has had some one off flings/crushes, but again those are an episode long, none of them have reoccurred, and we as the audience don't tend to care about them much beyond the one episode they are in.
I think Ferdafs did a great job expanding Tricia. She's fully a background character in the show, and I think her being in more episodes (and some of her dialogue such as: "Summer, I want to fuck your dad") is due in part to the porn community. And her continued inclusion/character portal is the show is the strongest evidence that someone on the writing staff has played some of Ferdafs game.