for the record, Avdol was not brought back due to fan demand, Araki himself clarifies this in an interview for the Jojonium Releases
....I didn't intend to erase him forever, though.. But I thought it'd be too easy if he came back to life immediately, so I wanted to prepare a flashy comeback that readers would be able to accept. When I draw JoJo, I never plan out the small things. In the end, I managed to bring Avdol back just before they reached Egypt, but I never planned that beforehand. It was just an idea that came to me while drawing. Now that I think back on it, since I removed him once, I probably should have made him more important in the story. Of course, these thoughts all come to me after I've already finished the story. Making the story center around Avdol would have been very adventurous at the time (Laughs); Even in the character popularity polls, I don't think he was ever in any of the top spots. Everyone just wanted to see Jotaro fight... Also, drawing Magician's Red was a bit of a struggle for me. If I had made a story centered around Avdol, I probably would have explored his relationship with his father, his upbringing, and his family. I'm pretty sure it'd become a mature story that wouldn't really fit in Shonen Jump. (Laughs).