Yes, girls can get angry at you over a lack of attention.
You went from texting her a lot over the course of a year to texting her a lot less.
Girls notice this kind of behavior and it can annoy them.
Also, the quality of your texts may have diminished tremendously because the focal point of your charm and attention switched to this other girl that could become a potential girlfriend.
So, not only is she receiving a lot less texts from you but they are also not as fun or interesting as they once were.
A girl can often tell when a guy is making less of an effort to have interesting conversations with her and that will often make her feel like she is not worthy of his time.
A sentiment like this will also annoy a girl and make her start acting up in the way she has been with you of recent.
By blocking you the minute that you joined a stream that you were not invited to, she was reacting emotionally and trying to send you a message that if you are capable of treating her as though she is not worthy of your time, she is capable of doing the same.