Zakura developer Adam Tucker stated that a single published shielded address exposes payment histories until Project Tachyon's recursive proof upgrade deploys.

From the articleZcash Builder Zakura Proposes Per-Swap Viewing Keys to Close a Quantum Privacy Gap - UnchainedAlso in Zakura Proposes One-Time Viewing Keys to Stop Quantum Linking of Zcash Swaps, Zcash Developer Zakura Proposes Fix to Stop Quantum Computers Linking Shielded Swaps - Decrypt