I know quite a few people think that that Maya picnic scene, with her saying they should all have "no strings attached", goes against her character, but I actually think it's an evolution of her character.
For the first 4 episodes, it's felt as though Maya has really defined herself and her life by her relationship with Josy. She depended on Josy so much for comfort and assurance because, apart from Derek, it seems like she didn't get much support or encouragement from anyone else, not just with their relationship, but in general. She also didn't know how to cope with them being apart and with the possibility that the relationship was going to end, and she also seems to have put a lot of weight into the relationship being her only chance at happiness and about what would happen in the future, as evidenced by M&J's hopeful plans to be together when they got to college that also briefly fell apart.
All of this meant that, when another promising, albeit surprising, relationship opportunity came along, she wasn't open to it, and she regrets not being open to it because of her dependancy on her current relationship and how she let it define her. So when she talks about "no strings attached", I think what she's realised is that she can't let a relationship define who she is and that she needs some time to really get to know herself and what she wants before committing to a relationship again. The same goes for Josy and the MC because they all rushed headlong into things, and they need some time to not only get their minds right, but spend more time with each other to see if this is what they really want.
It's a quick turnaround, sure, but it also feels like a very mature decision from Maya to not attach labels so early on and to just see if the relationship can grow naturally by not having any expectations or strings attached to it.