You've got it backwards about the role of oxygen--it is being used to inhibit polymerization in this case. They are allowing oxygen to dissolve into a thin layer at the bottom of the vat so that the build doesn't stick to the membrane, and they can have a continuous draw.
The true build layer is actually within the liquid, near the bottom, but not on it.
From the abstract:
"...feature resolution below 100 micrometers. ... complex solid parts can be drawn out of the resin at rates of hundreds of millimeters per hour."
Key novel feature is the oxygen-permeable, UV-transmitting membrane at the bottom of the tank that creates a thin (down to 20um) inhibited 'dead zone' where the resin can't polymerize. They project the image for the current layer up through the membrane and the dead zone, so the build layer is actually within the tank. This means they can just draw the part up continuously from the top, with no stepping or processing needed after each layer. The thickness of the effective build layer can be controlled by adding a UV light-absorbing dye to the resin, which allows them to optimize for different print speeds.
https://www.youtube.com/channel/UC0JDc9dooc1xATvMdG7MMLQ