The machine always could, for newer machines they decided to mute it for some reason, there's an NVRAM setting, if you want to mute the chime again: `sudo nvram StartupMute=%01`
That's just Apple deciding for the users, like it has always been doing. It's funny to see the setting for it is so hidden; my PC motherboard has a "POST beep" setting in the BIOS setup, which doesn't require a terminal in a working OS to get to, and whose presence is helpfully reminded each time I turn it on ("press DEL to enter SETUP").
It doesn't necessarily require a working OS - you can of course use either of the two recovery systems (On Disk, or Internet Recovery), a bootable time machine drive(IIRC) or an OS X installation USB Drive to do so.
I do agree however that the low level system tunables are unfortunately very hidden.