MATIC network back to ETH ERC20 - how long should it take ???

MATIC network back to ETH ERC20 - how long should it take ???

I need clarification please 

"Moving funds from Matic mainnet to Ethereum
Withdraw of funds takes ~3 hours in PoS and ~7 days in Plasma."

please explain - does this take about 7 days to go back into ETH ERC20 ???