You have to realise that the beeps you hear During a BIOS start-up sequence are different depending on the status of the start-up ...
With an AMI Bios, (or variants modified by OEMs), if all is well and the BIOS starts up without any issues it will give a single Short beep and then start the Operating System.
If there is a problem with the installed ram then the BIOS will Issue a Single Short Beep and Freeze the system, or stop with an error message on the screen ( this is the same exact beep as the one for a successful BIOS Boot), and you will need to use Ctrl-Alt-Del to restart the system, Other faults will generate different beep patterns and messages.
I have listened to your sound file, on the other thread, and it sounds to be exactly like the Beep I hear everytime I start my Acer Desktop, HP Laptop and Custom Build Main System
I agree that the fact that this beep sound may not have been audible prior to the installation of FCU and that is something that may be related to the new update, ( one of the BIOS options like Fast Start that windows prefers by default maybe?), but if the system is starting up well and not freezing or showing errors then I would not worry about it.
If you switch off Quiet Boot,and / or Quick Boot, ( and possibly the Show LOGO option in the bios), you should see a scrolling list of messages during the boot Includes Bios and Pre GUI Windows - If you see no error messages during this I would suggest that your system is booting correctly and safely.
If you would like to learn about the bios startup sequence and possible issues then this site is one of the better ones ...
BIOS Beeps - The definitions of Bios error beep tones | biosflash.com