Add notice re interop cluster

Author: fainashalts

pages/stack/interop/superchain-erc20.mdx

@@ -11,6 +11,10 @@ The SuperchainERC20 standard is ready for production use with active Mainnet dep
 Please note that the OP Stack interoperability upgrade, required for crosschain messaging, is currently still in active development.
 </Callout>
 
+<Callout>
+Please Note: SuperchainERC20s can be deployed on any chain, but will only be interoperable within the [Superchain interop cluster](/stack/interop/explainer#superchain-interop-cluster).
+</Callout>
+
 # SuperchainERC20
 
 The [`SuperchainERC20`](https://github.com/ethereum-optimism/optimism/blob/develop/packages/contracts-bedrock/src/L2/SuperchainERC20.sol) contract implements [ERC-7802](https://ethereum-magicians.org/t/erc-7802-crosschain-token-interface/21508) to enable asset interoperability within the Superchain.