Boy, I didn't see this theme coming! By the time I got to the appropriately backwardsly-wrapped revealer, ITSA WRAP, I had forgotten about the circles, and I was all "TSARNICHOLASI" is a wrap somehow? ... But no. As you have also figured out by now, the letters ITSA are found, in order, beginning somewhere near the end of the theme answers, and ending at the beginning. Sounds so simple, right?
Well, why not a theme like this, I suppose. Mr. Shortz has been overseeing the NYTX since 1993, and I'm sure he's constantly on the lookout for new and unusual themes. And who am I to criticize it? :)
The first two Across clues are especially covid-relevant to me. The first, SWAB (Sample collector) is covid-relevant to many people, of course, but TWANG (Banjo sound) is relevant to me and Frannie, because pretty much every Monday night for several years right up until March, 2020, Frannie and I would go to a local bar to hear bluegrass music. But since the pandemic started, I don't think I've heard a live TWANG even once!
Moving on, as we all must, I hadn't heard that a WOMBAT had cube-shaped droppings. Strange. And I also hadn't heard that the Economist viewed DATA as "The world's most valuable resource." I think that could be debated, but I'm not going to take the time to engage in ABATTLEOFWITS with its EDITors here. All I'll say is that, were I starving, I might prefer a sandwich to a spreadsheet. REBUTTAL?