why would you take the least charitable interpretation? there is no need to be hostile.

and the answer, of course, is that it can be, as long as the information copied is meaningful for displaying to the user.
you're basically asking the equivalent of whether putting things into an array is an algorithm, which of course has the answer "it can be, depending on how you put it in". so basically, the operation you're highlighting is not the point.

Not it isn't.

A command line literally is a UI.

You seem to be confusing GUI and UI?

This isn't hard, you're just trying to make it to be.

Memcpy from a file to a screen buffer is as much a UI as pouring water in a pot is a soup.

I did not make this definition. However, this does not give you the freedom to make up your own definition and treat it as a fact. Don’t spread wrong information.

I'm going to go with no, since that step is not transferring data to a human, it's transferring it internally within the computer.
UI can refer to either the medium, such as a visual display, speaker system, or keyboard, and it can also refer to a specific layout of information (like the Qwerty layout, or a webpage layout). I wouldn't consider the USB protocol UI just because it can transmit HID Events, only the keyboard or mouse as a whole is UI.
You could almost call HID events UI, but I'd still argue they're more of a computer-device interface than a human-device interface