He’s not returning but that will still depends on what you saw as quitting, might just be he took a long break yet the main story will be the determinant..
let’s just assume he actually quit, it doesn’t works like that, such person would be tempted at all time so at some point you will be back to it and this time it could be with even more full force .
If he used to be addicted, then there’s tendency he’s still addicted and couldn’t hold it anymore.. what he could have done was taking breaks from time to time  while increasing the time intervals till he finally quit it, I guess that might have just worked.