I'm kinda curious what will this lockdown do to the efforts to replace their controller and/or firmware with something more open. Something like [1]

It's nice to have a private key to their cloud authentication, but ultimately it's the printers firmware that's the issue. While Bambu owns and updates that, they can change the keys basically anytime they decide that they had enough of the alternative Bambu Connect servers that people will inevitably create with the current keys.

[1] https://github.com/ChazLayyd/Bambu-Lab-Klipper-Conversion