Can miners reject merge of beacon chain and mainnet?

I read the information about ETH 2.0 on the Ethereum website https://ethereum.org/en/eth2/ but it has no technical details. I don't understand how the change from proof of work to proof of stake will happen. How will the beacon chain and mainnet be merged, as is announced on https://ethereum.org/en/eth2/beacon-chain/?

Will this be an Ethereum Improvement Proposal (EIP) on the mainnet to be voted on? If so, clearly there is a chance for the proposal to be rejected by a majority of miners. In this case I would expect Ethereum to fork into two chains, just like Ethereum Classic came into existence in 2015. There currently is some discussion on this subreddit as to whether this will or will not happen to EIP 1559 (change to Ethereum's fee structure). Or has this vote already happened in the past?