Transaction Confirmation between Users I'm reading this paper [1] that explain what happens when a user B wants to send money to the user A. The example says: 


  When the miner finds a hash value with the correct number of zeros
  (i.e., the discovered value is lower than target value), the discovery
  is announced in the network, and both the Bob and the Alice will also
  receive a confirmation about the successful transaction.


After that:


  The Bitcoin protocol rewards the winning miner with the set of newly
  minted bitcoins as incentive, and the hashed block is published in the
  public ledger. Once Bob's transaction has been added in the
  blockchain, he and Alice each receive the first confirmation stating
  that the Bitcoin has been signed over to Alice.


Now I want understand some points:


It's true that B receives the transaction confirmation?
It's always true?
Apart Bitcoin, if we talk about Blockchain, every user that
sends a transaction towards another user, will receive the confirmation?


[1] - https://arxiv.org/pdf/1706.00916.pdf
The first confirmation is simply the fact that your transaction was included in a block. Any confirmations after that are simply new blocks that extend the chain on top of the history that includes the block with your tx.

To be notified about transaction confirmations, all one has to do is listen for the broadcasts of new blocks, and check if their tx is in it, or if the block extends the chain after their tx has been mined. If either of those hold true, the number of confirmations is incremented.

Due to this, it doesn't really matter who sent coins to whom. Every participant on the network is notified of which transactions are being confirmed, since they all receive new blocks.