Well said
See, there you go again hyper focusing on one thing and blowing it up to match your want but ignoring the rest of the context.
Josy never said she was happy Maya wasn't there as if she only prefers being with the MC all the time. Her full comment was as follows:
"Don't take this the wrong way, but I like it when it's just us. I feel like our talks are deeper when we're alone. I mean, about you and me. When we talk about us and such."
You're only focusing on the first part and interpreting it in a way that is far greater than the sum of the whole comment. Because what she's actually saying is that she feels she can have deeper talks with him about each other when they spend time together. This, however, does not mean she prefers him overall, only that she feels it's easier to talk with him. Cut to her conversation with Maya later in the episode and we understand why that is:
"I think with everything you've gone through, I didn't want to bother you with my problems."
So what we have here is that because Josy was selflessly and somewhat detrimentally holding things back for what she thought was Maya's sake, this is why she felt good to talk to the MC about things because it's what she needed to do; to talk to someone. Josy herself made it difficult to talk with Maya not because it is or was difficult for a reason that amounts to them not being good together or anything like that, it was a self-inflicted wound on Josy thinking that she would be adding to Maya's problems, all of which is acknowledged in the very next part of their exchange:
Josy: "You already carry so much, and maybe you can't take it if I weigh you down."
Maya: "Have you been scared to tell me stuff?"
Josy: "Subconsciously, yeah. And it snowballed... And now it's this huge snowball that I can't push anymore."
Josy thought she was doing the right thing here by not burdening Maya further, but as she herself said it "snowballed" on her to this point. Then when she finally unburdens it all, Maya is so incredibly understanding and patient with her and showing Josy she needn't have held back like she did whilst also acknowledging how best to move forward and that is to not only be more open with each other but that she also needs to do more to support Josy. These are just some of the choice quotes that show all that:
"Tell me the things you've wanted to tell me. I won't break."
"You matter, Josy. You matter to me."
"I'm so thankful for everything you've done for me and how well you've supported me, but I failed to see that you were losing yourself while doing that."
"But I don't think we should postpone sharing these thoughts and having these talks anymore."
"We owe each other to be open about everything, and I'm sorry I've kept secrets from you."
"Again, we understand each other better than we think. We share a lot of these worries and thoughts."
"Let's make time for us and allow ourselves to dig in. And also, let me support you for a while."
All of these are pretty clear and positive expressions from Maya that can lead them to improving their relationship, especially when you couple them with Josy saying,
"I want and need that", with regards to working on their relationship and I think we are going to see that before anything happens with regards to any solo paths.
As for this, you're the one who seems to be forgetting that they agreed to deal with all this after the party which means they both agreed to really begin this process another day. So it's not that they forgot anything, they just agreed to enjoy the rest of the night without dealing with anymore heavy stuff and so let that slide for now.
Again this just feels like you are taking one little thing and warping it to your own viewpoint because of what you want it to mean which is, as
ChipLecsap put it, your cognitive bias. You're not recognising or acknowledging that they still have plenty of time to do exactly what they said they wanted to do after this night and are rushing to a conclusion that suits your best interests rather than acknowledging that they haven't even started yet which is how it actually is.