I feel like if you join an RP for any length of time, write some stories, have those stories interact with other people's stories, establish lore, and then quit for one reason or the other, it's a big ask to request that nobody use anything you created. 

I mean I'll accommodate a player as best I can if they ask, but if we've been RPing together for months or years how much of your ideas are really your own? If you RP bob and would like him removed from the RP after you leave then sure, we can write bob out. But if you've made bob the center of the story, have us 2/3rds the way through an arc, have an unresolved romance subplot with May's player, and additionally want me to make the acolyte subplot you started (and everyone else added to) go away, that's gunna play out a little differently.