The upcoming NU7 upgrade for the Zcash network, proposed under Zcash Improvement Proposal-2003, introduces changes that may render funds in the legacy Sprout shielded pool unspendable. The update will disable version 4 transactions, which are currently required to access these assets.
While the proposal does not involve burning the funds and suggests a possibility for future access restoration, developers warn that users might permanently lose the ability to spend their ZEC if it remains in the pool. Community members are advising holders to check their old wallets for Sprout-based assets before the changes take effect.
The NU7 upgrade is scheduled for activation on the testnet on October 6. A final decision regarding the mainnet deployment, targeted for November 5, is expected on October 20. Beyond the changes to the Sprout pool, the upgrade aims to reduce the target block time from 75 seconds to 25 seconds while maintaining the existing halving schedule.
