[Brian_K_White]

Actually ubuntu and/or some cloud integrator is violating principle of least suprise, which predates by even more decades and applies everywhere not just in a computer operating system.

Having /etc/ssh/sshd_config not do what it appears to do is inexcusable, however that comes about.

Even if the fix is no more than structuring the file a little differently so there are parts both before and after the .d loading, and comments that say what overrides what, and all the actual config files and default behavior are still the same.

[HumanOstrich]

That's just not how it works, and it never has. One of the main purposes of the .d files is to avoid modifying the distro's sshd_config file, so you don't have to resolve conflicts during an OS upgrade. Commenting your overrides in the sshd_config? That's backwards.

Downstream distros sometimes want to override the default settings. That's what .d is for. It doesn't violate the dogma "principle of least surprise", especially if you run `man sshd_config` and learn the first thing about sshd's config files.