The thing is, with potentially at least 3 more episodes of main story to go (according to DPC) it doesn't even necessarily have to be resolved in Ep 12. This next Ep could just be one where the MC realises it's not been going as well as he might have thought, kind of like how Maya didn't seem to think the communication between her Josy was as bad Josy thought it was. So by the same token, the MC may not be very aware of issues involving himself and his communication with the girls not to mention the fact of not giving them an equal amount of his time.
With the conversation they have at Bella's, it feels like a "reset" moment for them, and a proper one this time. For the first time that we've seen, they've properly opened up to each other about their issues and concerns instead of just "following the stream", as Josy put it, by simply sidestepping them in order to focus on resolving Maya's loan situation. If they bring this to the MC and they all realise things need to improve if they want this to work, it could be that it goes a few more episodes to give them and players that chance now that the characters realise they have things to work on. They can address any imbalance and maybe it could even be considered wiped clean in terms of the scene choices previously made and there will now be choices going forward that truly decide it.
As to what you said in that prevous post, I don't know if I'd go so far as to say an unachievable throuple twice in 2 games would be any sign of "prejudice", but it certainly isn't the best thing a dev can do to keep playing around with their audience like this. And yes, he'd never make the monogamous MG branches impossible to achieve no matter what choices you make, so it really would be incredibly unfair to do this to a MG branch just because it's a relationship with 2 girls.