Merge pull request 0xPolygon#2577 from 0xPolygon/Sharonbc01-patch-1

Update forkid-9-12.md

Author: mitchpolygon

docs/cdk/how-to/migrate/forkid-9-12.md

@@ -19,9 +19,10 @@ See [Example Maintenance Communication to Network Partners](#example-maintenance
 The high-level steps in the collaborative process are:
 
 1. Implementation Provider halting the sequencer,
-2. Polygon executes the upgrade transaction,
+2. Implementation Provider can send & executes the upgrade transaction,
 3. Implementation Provider upgrades components to Fork 12 stack,
 4. Implementation Provider restarts the components.
+5. Polygon updated the Permissionless node attached to the Agglayer for that chain.
 
 ## 2. CDK Components Versions
 
@@ -90,7 +91,7 @@ go run ./zk/debug_tools/datastream-host \
 
 ## 4. Polygon Preparation Steps
 
-1. Polygon will collaborate with the Implementation Provider to **schedule** the UTC timing and dates for the upgrade, incorporating required timelocks.
+1. Polygon will collaborate with the Implementation Provider to agree on the scheduled and dates for the upgrade which will incorporate any required time locks.
 2. Polygon will set up Google Meet calls between Polygon and the Implementation Provider's engineers to conduct planned upgrades for both testnet and mainnet on agreed dates.
 3. Polygon will prepare in advance and with agreed timelock:
     - Rolluptype for fork 12
@@ -102,10 +103,7 @@ go run ./zk/debug_tools/datastream-host \
 
 **Please Note:** To avoid creating reorgs or other unwanted situations, it's important that all L2 transactions are verified before performing a fork upgrade. This means all batches should be closed, sequenced, and verified on L1.
 
-### Steps to Halt the Sequencer
-> 💡 Please note: For an isolated chain not attached to the Agglayer the chain admin can  perform operational step 4 on their chain’s rollupmanagercontract. 
-Polygon are not involved. Please check the [upgrade procedure for isolated networks](#contract-upgrade-procedure-for-isolated-networks).
-
+**Please Note:** IP Partner Rollup admin can send & execute the fork ID upgrade transaction.  
 
 1. Stop the sequencer.
 2. Reconfigure the node to enforce sequencer stops at a specific `batch_num`:
@@ -151,7 +149,7 @@ Polygon are not involved. Please check the [upgrade procedure for isolated netwo
 
 3. Stop all services (node, prover/executor, bridge).
 
-4. **Polygon:** Upgrade the Smart Contract (multisig):
+4. Implementation Provider Rollup admin: Upgrade Smart Contract (multisig):
     - Upgrade rollup to fork 12.
     - Wait for the Tx to be finalized.
 
@@ -193,8 +191,8 @@ Polygon's DevOps team will be accountable for upgrading the Agglayer permissionl
 
 ### Post-Upgrade Validations
 
-1. Test batch lifecycle.
-2. Test the bridge.
+1. Implementation Provider will test the batch lifecycle.
+2. Implementation Provider will test the bridge.