>>212407056 (OP)1. Appollonia is barely a character in her own right, but she's Mikey's last shred of human decency. She represents the alternate path where Mike marries her, and they live a quiet normal life. He learns to NEVER trust anyone, never let your guard down, and to never
There's a direct parallel with Apollonia's death and the assassination attempt on him and his family. You can't understand his reaction to the latter without the former.
2. A bunch of other plot shit is still going on in NYC that culminates in Sonny's death, which results in the peace summit, and Michael coming back.
3. Michael literally can't come back until things quiet down.
They can't just timeskip the Italian shit, it's important.