In theory that would be fine if devices continued using the same amount of energy. Instead of charging my phone every night, if I charged it every six nights, it doesn’t need to last for as many charge cycles either.
A lot of compute on devices is currently battery limited. Manufacturers try hard to keep a charge at one day but don't really care beyond that. If we instantly replaced batteries with ones that lasted 5x longer and lasted 1/5th the cycles, I'd expect phones to instead use 5x the power in a single day since all of the metrics that currently resist waste right now would not longer be launch blockers for power-hungry features.
They also mention a rapid drop-off in capacity after the first cycle in the article itself (3600 mAh to 1200 mAh). The main point the authors are making is that the discharge process is rechargeable rather than a single discharge. The press release uses this finding to make rather ambitious claims.