e-beam lithography has lots of benefits, but it is extremely slow. This technique increases its speed by a factor of 10,000 by using parallel beams.
The article points out one advantage: you no longer need to create a mask, and the cost of the mask is drives the cost of the photolithographic process. Masks have become extremely challenging as feature sizes dropped below the wavelength of the light used for the photolithography: the mask is no longer a simple reproduction of the shape of the desire result. Rather, the mask (rather, the masks, since "double-patterning" is needed) have funny shapes that cause the light to interact with the surface based on the rules of optics,and not all desired results have corresponding masks.
But there is another consequence that is even more important: A mask is so expensive that you must produce a huge number of parts to amortize the mask cost. For E-beam, you can spefiy the exact result you want, and the beam can produce that exact result. But even more importantly, there is essentially no penalty for creating multiple different kinds of devices on the same wafer. This completely changes the economics for creating experimental devices and for small production runs of ASICS, and it allows the industry to re-open the idea of wafer-scale integration.
E-beam failed because is was too slow, and it lost ground to photolithography as the wafers got bigger and the feature sizes got smaller. But suddenly we have parallel e-beams, which conceptually increase the speed by number of parallel beams (currently 10,000.) But if 10,000 now, why not 1,000,000 in the future? We get to the point where a specialty fab could produce a single instance of an experimental custom device for not too much extra money, and suddenly we can create a small quantity of ASICs for $100 apiece.