It doesn't lined up at all, when Josy moves out Maya says nothing about Patrick ultimatum not one word. You can assume they happen at the same time but there is no proof in the game.
Their words literally are the proof because the timing of them lines up perfectly.
We know for a fact that they weren't able to see each other over the summer. Josy literally says that them having to separate like this feels
"exactly like it did before summer". We also know for a fact that Patrick's ultimatum was that Maya
"couldn't see Josy ever again". So it's as clear as glass from this that Patrick's ultimatum lead them to stop seeing each other over the summer and them separating like this because of Patrick's visit reminds Josy of that.
I really don't know why you're fighting this other than just more cognitive bias in wanting to believe that cracks had started forming before the ultimatum when it's clear the separation forced upon them is when it all started to show.
It is very lazy to blame Patrick and even the girls know that now or at least starting to realize it as shown in ep10 and 11. Maya isn't more comfortable with MC then Josy because of Patrick if her father was the problem she would never had say that, there problems are with each others and there isn't any way around it.
It honestly can't be denied that if not for Patrick's ultimatum keeping them apart then these issues wouldn't have been brought to the surface in the way that they were. And by issues, I simply mean what I've been saying this whole time, which is their communication, something that is vital to do right in order to have a successful relationship. That's literally the primary thing at the heart of all this, having more open and honest communication and not bottling things up to the point where they fester as they have done with Josy. Because only by doing this can they work through issues they face and not let themselves be overcome by negative thoughts and feelings that would harm the relationship.
It's a hurdle all relationships must go through, as I've been saying, and this incident really hammered home that it's an area they've been remissive in as often happens in young, teenage relationships, as I've also been saying. So that's why I say Patrick was the catalyst for this issue coming to the surface because it had them face a hardship that, at its resolution, made them realise what they need to work on.