AITA for refusing to leave my room early for the new roommate?

I (26F) lived in a duplex with three other female roommates. We lived on the lower level and the owners of the house lived on the second floor. I lived there for about a year, and then I decided to move into a townhome with another friend. I gave the owners plenty of notice that I intended to move out the beginning of August.

Mid June, the roommate Erica (28F), who had lived in the duplex the longest and acted as the liaison between our unit and the owners, asked if I could move out mid July. A recent college graduate who the homeowners knew was planning to move to the area (she got a job in our city) and she needed to start her new job in July. She was going to be taking my spot in the duplex. I looked into the situation, and it worked out for me to move out mid July. I agreed and thought all the plans were set.

The end of June, Erica told me that the new girl was coming down early to get settled in her new room before she began her job. This meant, according to Erica, that I needed to move all my things out of my room ASAP so that the new girl could move in. The problem was that I couldn’t move into my new place for a couple weeks.

I’m not quite sure how it was decided the new girl would come down early, but no one asked me. I was just told that it was happening. They said I could put all my stuff in the dining room (it was a large room) and still sleep on the couch at the house. I thought about it a little and said I wouldn’t be moving out early; I would move out mid July as agreed. The new girl came down early anyway and slept on the couch in Erica’s bedroom.

Erica told me that I was being selfish and I should have moved out for the new girl, that she is wasting her time by coming down early and not getting her room set up.

She also said we all have to look out for each other and that she is inconvenienced by having the girl sleeping on her couch. I responded that it is a different thing sharing a room versus completely displacing myself. Plus, it would have made more sense to ask me if I could vacate my room in early July before anyone told the new girl she could come down. But I wonder if I ATAH since I refused to leave the room?