That page looks rather dated. Yes, I think your idea is correct but it also depends what crowd you’re referring to. Ideally, all Whonix users would have the same screen resolution. May not matter what other Debian users do, since Whonix doesn’t hide itself.
I would argue that using Full-Screen is important for behavioral reasons - so you don’t shoot yourself in the foot by accidentally confusing Host & VM windows. For example, using Qubes, it’s possible for me to have multiple windows open from multiple Workstation VMs. Even though the windows are color-coded, it’s easy to type accidentally in the wrong window. I actually take it one step further and use a separate virtual desktop for each vm: host / dom0 / gateway + workstation1 + workstationX…