The new MacBook Pro does away with the classic Mac startup sound that's been present on Macs for the past seventeen years, probably to avoid annoying users as the notebook automatically powers on when you open the lid. But rather than completely kill the chime, Apple's disabled it on the new MacBook Pro.
Thankfully, you can re-enable it with a simple Terminal command.
We think this could mark gradual phasing-out of the familiar Mac startup sound just as the one-port MacBook with USB-C has spelled doom for Apple's proprietary but love MagSafe connector. Here's a brief history of the Mac boot chime.