The OP wanted to know what happens to the items in FBA, not how to retrieve them.
I’ve had “The Talk” with my husband and told him that while he could contact Seller Support and have the account closed, why do it? Everything’s at FBA, so money will just keep getting deposited to my account (which he has access to) for years to come.
I told him to just transfer the Amazon account ownership to him so he gets the emails. That’s all.
This is one of the BENEFITS of FBA.
But hey, if FBA is Big OOGA BOOGA to you, don’t let me dissuade you. There’s more than enough crud in the warehouses already.