Correct. This will likely cap the rise in Zinc TCs at least in the short term so this is positive for NCZ so they should be selling as much as they can now given Glencore/MMG may be shipping at lower rates for the next month. However given the disruption is on transportation and the mines will continue stockpiling material so once the rail line come back online the TCs should spike up again given they will be selling the backlog.
https://www.reuters.com/article/us-australia-floods-zinc/australia-flooding-to-disrupt-lead-zinc-concentrate-rail-shipments-idUSKCN1Q20M6