Grease is needed to lubricate the balls so they are not in direct contact with the races. Without grease the balls/races will fail rapidly when under load. There is no load on the cages so I fail to see how this development helps at all.
Let me quote a key passage: "Engineers must check that films are sufficiently thick so asperities — peaks of surface roughness between mating surfaces — don't touch. Otherwise, bearings can rapidly wear and fail."
