Deleting data-blocks, "unmaking" assets, loading a .blend without UI, etc shouldn't cause the Asset Browser to reference invalid data.
It currently references the preview and asset-data of asset data-blocks. This is fragile.
We already store the `ID.session_uuid` and could use that to sanity check the references before access.
Besides this memory issue, we could just make sure the file list is refreshed for relevant notifiers while //Current File// is shown. If the list still ends up being outdated then, there at least won't be a crash/undefined behavior.
Also see T82162.