It being such a quick and easy fix this early into the story has me entirely convinced the Maya/Josy relationship is going to explode. The plot for them wont be like the other girls where a relationship forms and matures, it will be a relationship exploding and the ending will be born of filtering through the wreckage. None of the other main LI are a fraction as far along (relationship wise) as Maya/Josy/MC. They're currently at the point most VN's end with the MC in bed with his harem.
It failing would make it a unique route. All the main LI have a very distinct "type" of a relationship story wise. DPC has been clever to diversify his girls and their motivations. Maya/Josy being a failing relationship would make it stand out as distinctly as Bella being confused about her feelings or Sage being so defensive and trying to keep it casual. It would also be simple enough to write and be interesting. Who wants 16 episodes of Maya/Josy just being in love if you're just their friend? They can implode regardless of the MC being involved, sure it will take a lot of alternative scenes with them to account for the MC being either a friend or a part of it but Maya/Josy can fall out over this regardless of the MC being a third wheel and it would make for an interesting drama fuelled story and it also primes them to be separated and let you choose between them. Easy to make solo routes if they're not together.
At the end of the day, DPC has said he might go as high as 20 episodes. It's waaaaay to early for a happy ending. I think this resolution was just priming Maya/Josy to be a drama filled clusterfuck.
It could certainly be filled drama, yes, and there's definitely a path for the MC to become romantically involved with one or both of them if you choose to just be friends, but I don't know if I'd go so far as saying it's destined to fail.
Yes, it does seem to have been resolved quite quickly, but I put that down to their shared feelings for the MC. Essentially, Maya and Josy aren't mad at each other because they not only understand how much they hurt one another but can also understand why they did what they did with the MC because they both feel the same way about him. They both fell for the same guy and for the exact same reasons, so it makes it easier to forgive each other when they're feeling the same things.
Any drama in the threeway relationship is likely to be caused by outside factors, like Tommy and Quinn, as well the MC's continued relationships with other women. Tommy's not likely going to be happy to find out that not only is his maggot son dating his step-sister, but that his step-sister is also dating a girl, and Quinn being a total wildcard and certified bad-bitch could try to sabotage their relationship for shits and giggles, or try to blackmail them into doing things for her because they'll undoubtedly want to keep it a secret. But it could also be affected by the MC continuing to see Jill, Bella, and Sage as this could cause jealousy and hurt feelings with Josy and Maya if they feel that he isn't as committed to their relationship as they thought he was (as ironic as that would be), or it could lead to Josy and Maya getting much closer because the MC isn't around all the time and whatever feelings they had for him disappear and they realise they don't miss want him as much as they first thought.
As for the friend-zoning path, I certainly can't see it being the case that the MC will never have any more interactions with Josy and Maya beyond seeing them in class and at parties. I could definitely see them struggle with what they're being asked to do by the HOTs, not just with the scavenger hunt but in general, and that they would come to the MC for help, which could certainly lead to some sexy fun time, even though he said he just wanted to be friends. I can also see this struggle with the HOTs leading to more fighting and arguments that draw one or both of them back into the arms of the MC, and that this will either lead to a second chance at the threesome route or individual routes for Josy and Maya.
As for the idea that this game could have 20 episodes, I admire the ambition and sheer amount of planning and dedication that would be required of DPC for that, but think about long that would be before this game is done. If each episode takes 4 months at the least, then starting from the last update in January, that would mean the game would be completed in roughly 5 years and 4 months (May 2025). If each update takes 5 months, then that would be 6 years and 8 months (September 2026). That seems a little excessive to me, not to mention torturous on both the the dev and the players and maybe an 8 episode limit like Acting Lessons would be less strenuous for everyone.