The first image shows a preview pop-up—the existing behaviour that was introduced in Windows 7 and became mandatory in previous Windows 11 versions. The previews are good, but having to wait for the pop-up window to appear in order to select one window from a multi-window application is annoying. Everyone agrees on this.
The author specifically states that he wants the labels completely gone (emphasis added):
It's baffling that Microsoft can't get this feature right after three years with it being one of the most highly requested features.
A simple toggle to disable the showing of Windows titles could have been added, or Microsoft could have replicated the Windows 10 feature many of us requested.
What TFA wants isn't an option in my Windows 10 settings, either, despite what he claims; I think it might have existed in Windows 7 (and earlier 10 builds?), but it doesn't exist now. I'm guessing he's in a very small minority of people who ever used it this way.
That said, if I recall my old registry black magic correctly, the maximum taskbar button width used to be based on the size of the caption bar for iconified windows; a remnant from early builds of Windows Chicago when programs still minimized to the desktop (something similar can still be occasionally encountered in MDI applications or when Explorer crashes). The setting should be somewhere in HKCU\Control Panel\Desktop\WindowMetrics, but I don't see anything that looks like a likely candidate; must've been removed at some point. Back in the days of NT 4, I distinctly remember using taskbar buttons that were extra-wide, just for the novelty.