I doubt this will happen at all in the years to come. Remember we are talking about fap games, about slightly interactive CGI-Porn for nerds and everybody else with enough imagination to cum for a render. This genre is doomed to cater to the masses, bringing the most easiest and sought after route to release pressure. Given the Patreon success of some projects and the failure of others it is clear for every amateur developer to better bring the standard male-MC-harem-incest-taboo-route if they want to earn some money, because that's what the guys want.
Yes, we have some games with a more fleshed out and interesting story, we have some games with female MC's, and yes I'm sure there are guys out there who play these games only for their story and characters. But the 99% don't, they want hot renders and fast actions, clicking through the text to get to the next picture, missing every hint and idea of the game, leading them to this forum to ask for walkthroughs.
If you ask me, this will stay the standard, for everything else you would need a far broader audience.