I certainly don't know, but I would predict it will be harder to squeeze back into uncomfortable or marginally uncomfortable shoes, and heels of much, if any, height.
What I don't know is whether workers will want to express themselves with more fashion-forward looks and colors--an example might be white or bright sneakers or typical obvious logo ones, vs wearing dark sneakers that sort of overlap with "work shoes".
Because if you look hard enough, you can find somewhat conservative clothing in more comfortable fabrics and fits--ponte pants, knit blazers, elastic waists and still put together even more than business casual outfits.
When I recently reviewed some of my black workwear pants, I recognized that in addition to quite tailored wool pants, I also had 2 pair of ponte pants with wide stretch waistbands, a cotton blend elastic waist slim pant, and an elastic waist slim wool pant. I used to work a lot of weekends and holidays, but did not "dress down" significantly, so these items were often FFBO. I can see that they also may prove to be good "keepers" as versatile even for pretty casual wear (not hiking!), travel, quick dress up with a jacket, and as comfortable as more casual pants, and more so than jeans.
Or will people want to just wear their regular T shirts and sweatpants?