I felt the exact same way when I played eps 1-4 and then again when I played ep 5. I've honestly never been hit so hard by an adult game before or been so emotionally invested in the characters and sometimes it almost feels like a form of self-harm to keep putting myself through it, but I will soldier on.
I don't know if DPC has ever specifically said anything about not liking threesomes, but I feel like the whole point of that moment in AL was to just inject some drama and really subvert people's expectations in a tragically emotional way.
Considering the flak they got from people about it, I'd be surprised if they don't have a happy throuple relationship as one of the possible endings in this game.
Well, as many people including yourself have been saying, this game is entirely different in tone and theme from AL. Yes, like AL it can tug at the heartstrings and make you feel for the characters, but it doesn't necessarily mean we'll get really heavy shit like death, psycho stalkers, and cancer.
Some writers can be diverse in their writing and write really serious and hard-hitting drama one minute, and then write a blockbuster superhero epic the next. DPC could be one of these diverse writers, we'll just have to wait and see, but I think AL gives a false impression of where this story is going because their first story doesn't necessarily define their style.