OpenAccess will not do such an automatic removal from _all_ containing collections. However, with managed inverse collections and the [Depend] attribute it is possible to just remove an instance from _one_ collections and get that instance automatically marked for deletion. With inverse collections one is also able to just nullify the inverse reference and remove it from the scope, but this will not remove that instance from other already loaded collections (no depend then!).
This gets philosophical easily: Its is trivial to know what I reference, but it is hard to know what is referencing me.
the Telerik team