Why Did Beta Install Give me a Boot Chime?

The Issue: My Mac (2018 MBP 15” with Touch Bar) is a model N/A to Boot Chimes.



The story in full:

Last night, I backup my MBP, and then installed the macOS 10.16 Beta. I did so in order to work with the macOS and give feedback - I worked with it a few, and started to notice a Boot Chime.


So, now that I got with a Boot Chime, I reset the SMC and the NVRAM and booted into Safe Mode. To no resort, the Boot Chime remained.

Having given feedback, I backed up the macOS, informed Apple Support via chat and was told to call Apple Support being that this is “intriguing” to hear, as My Mac (2018 MBP 15” with Touch Bar) is a model N/A to Boot Chimes.

So, I called Apple Support back. I showed them the noise, I erased the partition, and reinstalled the macOS anew. Still - there is a Boot Chime. So, I erased the partitions, and moved ahead with a Boot Chime.

Right now, I am restoring my Mac to a TMB prior to yesterday. It will take a bit to get complete.  Any Thoughts as to why I would get a Boot Chime after installing this Beta Software (macOS 10.16 Big Sur)?  As mentioned above: My Mac (2018 MBP 15” with Touch Bar) is a model N/A to Boot Chimes.
There is a new preference option to enable/disable the boot chime in System Preferences (can't remember where) even on newer Macs.
Disable "Play sound on startup" in System Preferences > Sound > Sound Effects.
Why Did Beta Install Give me a Boot Chime?
 
 
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