maybe that could be implemented in a wallet program,but not in the blockchain
the blockchain is just data. it holds no programming or code. just a list of transaction blocks.
the code part is done by wallet apps to relay transactions out, and to display confirmed transactions..and other code in mining software. as i said nothing needs to be done to the blockchain data apart from continuing to store transactions that are in solved blocks.
its for the wallets and miners on the outside to change their protocol on which transactions end up in the waiting list for the next block