All true. but as you pointed out some of this simpyl came from the fact that MC is the protagonist.
Now before, episode 3 ending we do not know that Josy and Maya are a couple. So any interaction between them would spoil it the twist. Because of this we can't say for sure, that they did not talked with each other. Josy pointed out, that Maya was Texting her, and each of her message was meaner before the one before.
May be they were arguing because of the fact that Josy . was planning to leave and throw the towel.
all in all both of them kind of felt like their relationship is mostly over.
of course, once they reunite the flame sparked again, but not without the mark of the past, and with MC in the picture.
the Josy MC Gym thing, is still a question for me, will it have actual storyline, or it was just used to catch Chad and Troy.
Maya had certainly not told her about the free tuition, as she explained everything to her on the evening of her arrival.
Maya may have known about Josy's fear of not being admitted and her plan to change her life anyway, but as we are told, they just don't talk about it, they just argue.
Certainly MC's role in the story pushes him to the forefront, but even if we delete him, it remains that the two girls don't know how to talk to each other, they can hardly ever say what they feel.
precisely because of MC's role I didn't talk about what the girls (especially Josy) say to MC in case he's not in the trouple, let's consider those (terrible) words only functional to the plot.
but there are other moments where certain choices are marked: for example for the arrival of Josy's father, she could have asked both of them to accompany her, or asked Maya first, instead she didn't. DPC purposely makes her ask MC, with Maya evidently being disappointed.
if MC wasn't with the girls at the beginning of the seventh chapter, Maya's father would probably have left the room attracted by the couple's argument, with Josy reiterating that she wants to live a sorority life in college, not watch movies in her room with Maya, it's her wish to live experiences far removed from Maya's character, then if Maya comes to HOTs it's not a problem, but she wants to go.
when Mc and Josy talk about it, for Josy it's Maya who has given up, who doesn't even try to make things work, and another time the communication between the two girls has been completely shut down, either Maya goes to the HOTs or there's no other solution (without MC)
and in that the invitation to the gym, to emphasize that Josy enjoys spending MORE time with MC than spending time with Maya, the classes are enough.
I know that it's a pretty silly pastime, but I have no other way than to judge each character's behaviour to form an idea about her (otherwise I'd only have to rate boobs and ass) and I can only do that based on what I see