Posing a foursome is not difficult, but DPC writes from an animation and DPC sex animations are very good. He takes into account all the movements of body parts and it makes a difference whether you do this with 3 figures or 4 figures. It also depends on the scene itself. What if all 4 are working at the same time? The MC lies down and fucks Sage. Meanwhile, Maya fucks Sage's ass and Josy sits on the MC's face while kissing Sage at the same time. That would be a challenge.
It would have been a very strange scene, especially considering Maya had never shown her dominant side, and even the opposite.
If you want to see how foursomes are likely to be presented, you can watch foursome sex scenes from the NLT games. There aren't many ready-made packs of such scenes and they are repetitive.
And besides, there's not even the slightest hint of a foursome other than some words from Maya. The unremembering between Maya and Josy is growing, the player has to balance, and so early on they decide to have a foursome?
If it does happen, it's only in the season finale, as something that's supposed to re-solidify their relationship.
I didn't read it that way or I can't remember it exactly, but I'll take you at your word. But that doesn't automatically rule Zoey out.
I strongly suspect that the foursome will have the MC present because DPC isn't known for showing us lots of or elaborate sex scenes without the MC. Therefore the whole thing will take place in a familiar environment, probably in the MC's room.
Zoey's arc ended halfway through at the end of ep10 and I expect a logical continuation for her in the form of a big solo scene. Now that she's realized she loves him, she'll admit it to him which will lead to a big scene. Given DPC's love of symbolism, this could take place against the backdrop of a snowfall or something.
Another option is a threesome between Johnny Boy, Elena, and MC. This is a really new experience for DPC, he's never animated a scene like this before.