I'm well aware of the "Electronic record search" that you are talking about. However, you missed the fact that these due-diligence procedures fall under the "preexisting accounts" section. The definition of a "preexisting account" is an account that has been opened on or before 31 December 2015. Therefore, your whole explanation for a "newly opened account" is wrong. If you check︀ the information for "New individual accounts", that is, accounts opened after 31 December 2015, you︁ will see no such information about "Electronic record search".
You are also wrong about the︂ fact that banks do not rely on self-certification when there is a change in information.︃ When, for instance, a new address is given, they need to send out a self-certification.︄ If the self-certification fails or is not accepted, according to the same document you linked,︅ the bank has to rely on the previous information of tax residence.
I have heard︆ that some banks might have their own rules so I cannot say you are wrong︇ on that. However, N26 does not seem to have the same information up on their︈ website anymore. May I ask where you found this information?