This article is focused squarely on specialized packaged tours like safaris, and on a hypothetical future state which no one can reliably foresee right now. I assume that many people on this forum who take RS tours would gladly "pencil in " their reservation for next year too if possible (but looks like schedule is unknown now). My hypothesis on that is it's a way for people to feel like they're exerting control (over an uncertain future), and maybe the only option they have to exercise their IOU vouchers they've received from these vendors for having to cancel their trips in 2020. I would guess that cruise ship schedules are getting filled despite any certainty of what will happen in 2021. Anyhow, this FOMO (fear of missing out) doesn't affect me personally, as I don't partake of packaged tours (I took exactly one with RS). I also have no desire to make any travel decisions now, or even for next year, when things are so up-in-the-air, so to speak.
The article makes a good point. Bookings are only place holders; they may not end up reflecting reality. Lots of things can change at an unpredictable time like this (job losses, changes in health and other personal circumstances, tour availability, etc) that can affect whether those future trips actually come to fruition.