At this time, the card number will change for all replacements, no matter what the reason is. Though we currently log the replacement reasons for statistics and operational purposes, all replacement reasons are treated the same.
We have some support for issuing new cards under the same long card number, however it is not complete yet. Being fully honest, we did not expect anybody to have needed to go through replacing their card for non-loss/fraud reasons more than once yet (CA preview to a full or investor card for example)!
As for the PIN changing, did you order one of these cards through in-app chat at all? The PIN changing typically indicates that a new card was ordered, rather than using the in-app replacement button where the card would be configured with the same PIN as the one it was replacing.
In either case, I’m so sorry that this has happened. This is 100% not the experience we ultimately want to provide.