No they won't. On the server end, the database requirements for that chest are a primary key and a few bits of data. Anyone who has it will have more data tied to their specific copy of it, but that applies to every item. If you can store 200 clothes, it doesn't matter in the slightest to the server which 200 clothes they are or which expansion they're from.
They'd only have to delete it if the client couldn't handle the data requirements to have all the models, and with the PS3 gone that doesn't seem like any kind of urgent issue.