I understand for other chains that MATIC is on, people would need to migrate their MATIC by sending it to a migration contract.
However, I’m trying to understand how the MATIC is upgraded to POL on the Polygon POS chain from a technical perspective because it is the native gas token of the chain and not a erc20 token. I understand that users wouldn’t need to do anything and it would be upgraded automatically as stated here: https://polygon.technology/blog/save-the-date-matic-pol-migration-coming-september-4th-everything-you-need-to-know
The upgrade will be a hard fork. In this hard fork the native token’s ticker will change. This is already being tested on the testnet, but has no general bearing on anything else on the chain once complete - it’s basically just a rename via hardfork.
To go a bit more detailed, the native (gas) token of PoS is a claim against the bridge that can be redeemed for MATIC on Ethereum. This “claim” logic is what is being upgraded, so that the claim now represents a claim against POL on Ethereum. Since this “claim” logic lives on the L1 side, PoS doesn’t know this change is occurring. The proposed Hard Fork that will upgrade the MRC-20 and other utility contracts is a nice quality of life upgrade to make PoS aware of this update and help devs/dapps update their UIs accordingly.
MATIC on Ethereum is the needs to be migrated via the migration contract as it isn’t represented as a “claim on something else” that can be upgraded/migrated, it requires a direct migration itself.