Rovio has indeed rejected the characters from Angry Birds Stella. I quit playing Angry Birds Pop! after Rovio has replaced the Stella characters with the original flock, although I do like the original flock. Ever since then, I’ve been wanting them to at least appear in the recent games. And yes, I do agree with Rovio’s other flaws. I’m known as Se on Miraheze, in which Se is short for Seunghwan Lee, which is my real name, and I suggest you go to Atrocious Youtubers to know more about me and more.
Edit: Just tap on Mar9122’s name in the comment section of Mar9122 in the page about him by looking him up in Atrocious YouTubers Wiki and look for the name “Se” on his discussion page, to know more about me. Also, I suggest you look at Miraheze’s other wikis.