Does KIP-0010 require a hard fork to activate?

Yes, KIP-0010 requires a hard fork because it adds new opcodes to Kaspa's scripting language. A hard fork means that all nodes on the network must upgrade their software to understand the new rules — older software that hasn't been updated will no longer be fully compatible. Existing scripts and addresses are not broken by this change, but they cannot take advantage of the new opcodes unless they are updated to use them. For users and node operators, this means keeping your Kaspa software up to date is essential once this proposal activates.