Does "Erase Disk and Install Ubuntu" replace the default boot screen?

The Erase disk and install Ubuntu option will cause all partitions on the disk to be erased, including the protected system and recovery partitions. It will also delete all your programs, photos, music and any other files in all operating systems, including all other operating systems themselves.

When you install Ubuntu, the GRUB bootloader will replace the existing Windows bootloader, but it will not replace the HP Compaq notebook's splash screen that appears during boot before the Windows logo appears on the screen. The splash screen is a function of the motherboard that provides a visual cue for accessing the BIOS. Because the splash screen is determined by the computer's hardware, replacing the operating system will not have any effect on whether the splash screen appears when the computer is started.

If you are installing an Ubuntu guest OS on a virtual machine the Erase disk and install Ubuntu option will erase all the data that is stored in the directory that is dedicated to the new Ubuntu installation and then install the Ubuntu guest OS in that directory.

No. It won't replace the screen that say F12 for more boot options.
it is because that screen is displayed by an independent software called Firmware BIOS. First displaying F12 option it will show you Grub where you can select Ubuntu and it's advanced options