I don't know if there's going to be any incest at all in this remake, but from the ending of this remake update, I'm glad to see that the faux canon incest has been removed.
I do have to say though, this remake much like it's original are one of those games that makes next to no sense having a straight MC as opposed to a bisexual one. Like, fine I guess you can stretch the straightness if the player has sexual content with futa and femboys turned off, but if you have them turned on, there is no excuse for the player character not to be bisexual. Like, it's pretty annoying to have my MC complain about not wanting to swallow someones cum because "that would be gay", after I specifically turned on both Futa and Femboy content.
Having MC realize they're bisexual after coming back to life would be accecptable, but sticking with "I'm straight" will just be moronic long term.
By traditional sexuality concepts you'd be right. However, modern sexuality is far more complex then this. The protagonist is attracted to femininity, their gender is secondary in this case. Furthermore, the game treats all other characters as female, regardless of rather or not they have a dick. That's enough justification for the MC to be straight.
I myself am straight. But, I can get off to male on trans, or male on futa, regardless of rather or not they have a dick. However, the moment the male is on the gives a BJ, or worse, takes it up the ass, I'm completely done. I've lost all interest in the content at that point. I can even enjoy SOME trap, especially if the character is treated like a female. The reason is simply because in my eyes they are female, their dicks are just an accessory, not their identity.
Furthermore, if the MC was bi, it would be a major turn off for the majority of the community. Having dicks is already a reason why many avoid this game, but a protagonist who is attracted to penis? That'd be an absolute killer. Even though the dom/sub argument is true for real life, ignoring expectations is dumb.
Once the player is made bisexual, certain characters, primarily the traps, would be officially recognized as male. They would no longer be treated as female, otherwise being bisexual is pointless. Furthermore, the moment we treat them as male, the possibility the protagonist being on the receiving end of a dick becomes a very real expectation.
So, to summarize, it makes sense for the character to be straight, and making them bi would be detrimental to the game.