Who owns a Vulkan buffer after submission?

One release owner, named. Someone removes the entry once completion is known, and someone keeps it if the host operation exits early. Those may be the same component, but the design should say which. Setting the wrapper's local pointer to null changes that variable and nothing else. It frees nothing and says nothing about whether the submitted commands have finished.

Check where the retirement list itself lives. If its entries sit in temp storage that gets cleared at frame end while their buffers still wait on the GPU, the entries are gone before they've done their job. In Odin that means looking at which allocator the dynamic array recorded, not which one the context holds at submit time.

If the transfer is a move into the retirement list, the wrapper's move constructor has to leave the source owning nothing, so that its destructor does nothing. Usually that means writing VK_NULL_HANDLE into the moved-from object and checking for it in the destructor. Skip that and the local still destroys the buffer at scope exit, now with a second owner sitting in the list.

Moved-from objects are still destroyed. The standard's "valid but unspecified state" covers library types only. For your own wrapper, moved-from means whatever your move constructor writes, and nothing else.