What happens when an editor leaves a publishing house?I'm not sure how a publishing company that takes unagented stuff works, so I can't answer that question.
In my case, an editor my then-agent had submitted to left the publisher. It was a great publisher too. And my agent decided not to resubmit there. (I still often still think about emailing that publisher and explaining the situation, but I know they probably won’t take a submission directly from the author.)
But it made me think - what does an agent do if they submit to an editor who leaves? Does the editor usually give these subs to another editor or should the agent resubmit to someone else at that house? And what if the author had directly submitted to an editor at a house that takes unagented subs. Would does subs be passed along? Or in these cases (whether by agent or author) is it always best to resubmit?
If I've submitted to an editor who then decamps for greener pastures, I send the submission to another editor (usually). It can be the case that the now-gone editor was interested in this kind of book, and other editors are not, so there might not be someone to send it to, but generally there is.
And yes sometimes I've found out the hard way that an editor is gone (a bounce back on a follow up email) but generally editors send out an email blast saying "sayonara sweetheart, it's been good to know ya."
The problem arises when they don't so much decamp as move to another team. Often I will have sent the ms to another editor at their new house, and you can't send to two editors at the same place. Oh yes, ain't we got fun!
I never assume that a submission gets passed on to someone else, and you shouldn't either. If an editor leaves, it essentially restarts the shot clock.