They have used a slightly different cathode structure, with carbon nanofibers instead of nanotubes, and with a different electrolyte.
So, as shown by other posters, during the last couple of months there have been at least 3 announcements, from 2 commercial startups and from an university, all claiming to have solved the reversibility problem of the cathode in lithium-sulfur batteries, using either carbon nanofibers, carbon nanotubes or boron-nitride nanotubes, and the 2 startups claim that in a year or so such batteries may become commercially available.
Having 3 such announcements instead of 1, makes it much more believable that at least 1 of them is not overly optimistic, so indeed the lithium-sulfur batteries might replace soon the lithium-cobalt and lithium-nickel batteries, making the batteries much more affordable.
Edit: according to https://newatlas.com/energy/rare-form-sulfur-lithium-ion-bat... it is possible to address the degradation problem. So maybe this is not vaporware.