A blockchain or smart contract will most likely not replace a notary as such - at least it is necessary to assess the situation correctly from the point of view of the current legislation. But what is certain is that blockchain technology can become an almost ideal tool for registering transactions, registering property rights, inheritance, etc. processes where notaries who are not clean on their hands can change documents "retroactively", which is impossible in the blockchain
I think it's too early to say whenever Blockchains will replace notaries or simply remain as an alternative solution. Despite Blockchain's promise of eliminating the middleman, it's still not 100% efficient. One way or another, human interaction is required to make it work as intended. The main issue would be changing documents on a daily basis due to the Blockchain's immutable nature. You cannot do this without sacrificing decentralization. A centralized database is more suitable for this, although it would defeat the purpose of a Blockchain. This wouldn't be much of a concern since Blockchain technology is not meant to replace everything in our society. Just my thoughts
