Not only is this paper real: arxiv.org/pdf/2304.01393.pdf

But they actually made it practical:

We have implemented two ways to reveal the actual names present in an overlapping stack, when viewing a PDF file on a computer.

First, hovering over the stacked names should pop up a tooltip with the authors listed in their original order, as shown in Figure 1.

This feature works on many desktop PDF viewers (e.g., Acrobat, Evince, Firefox, VSCode), but notably not Chrome, Edge, Safari, or MacOS Preview. It also does not work on mobile devices we tested (probably because they lack a natural notion of “hovering”).