<human>: Can you give me a shortened version of the text?

I've been living in a flat for eight years and am the only person on the lease. My current flatmate moved in a year ago and things have been just okay. She mostly stays in her room and plays video games, has gotten overly defensive when called out on cleanliness issues, and seems to go to a "worst-case-scenario" whenever I have something negative to say. As an example of the later, when I originally brought up the idea of her moving out I mentioned a very forgiving timeline of somewhere between October and January (This was in early August). I asked her to take a week or two to thing of a timeline that would work for her. She somehow took that to mean I wanted her out in September. She was quite angry at me. I apologized and she happily accepted - though I didn't really feel like I had to apologize. I'm still bitter about this but I honestly don't think the two of us communicate well and I would rather just have peace between us then open up a row over it.

My girlfriend is going to need a place to live in October and I'd like her to move in then while flatmate continues to look for a place. When I brought this up with flatmate she said she would basically live full time at her boyfriend's house until the two of them find their own place. She would still be paying rent here and leave her stuff here while they hunt. She would be annoyed. I'm guessing she's pretty resentful that she has to move; when I asked why she would move she just said it, "Wouldn't be a good idea" if she was around.

Having just typed this out I feel like I may have exactly what I wanted: current flatmate with whom I don't get along with is going to move out and girlfriend with whom I am in love is moving in.

My question is, did I breach some kind of flatmate etiquette here? I knew I would be asking a lot of her to move out which is why I gave her a generous timeline.
<bot>: Asked flatmate to leave and seems cool with it, girlfriend needs a place to live, and flatmate is pissed I want her to live here while flatmate is trying to move out.