The Merge does not change any underlying of how Ethereum transaction works, in the user senses. So, there is nothing to worry about, it will still work.
The concern you raise is also addressed on the Ethereum misconception website, the Ethereum team explain it thoroughly:
Users and holders
The Merge did not change anything for holders/users.
This bears repeating: As a user or holder of ETH or any other digital asset on Ethereum, as well as non-node-operating stakers, you do not need to do anything with your funds or wallet to account for The Merge. ETH is just ETH. There is no such thing as "old ETH"/"new ETH" or "ETH1"/"ETH2" and wallets work exactly the same after The Merge as they did before—people telling you otherwise are likely scammers.
Despite swapping out proof-of-work, the entire history of Ethereum since genesis remained intact and unaltered by the transition to proof-of-stake. Any funds held in your wallet before The Merge are still accessible after The Merge. No action is required to upgrade on your part