Might be useful in limited applications, but at the penalty of less reliability and greater weight. To make it truly useful, the gas reservoir needs to be able to regenerate, like motor vehicle air reservoir systems for air brakes and auto-inflate/deflate, and then we're talking a great deal more complexity and a great deal more drivetrain resistance if you human power it.

There could be a battery powered compressor option, but that too would be weighty, even with Ping batteries, and to make it light enough for a bicyclist to use, the cost would be very high, or the reliability would be low, from an engineering point of view. There'd still also be a battery charge time limit, as well. This could be offset by solar cells, of course, but this leads into even greater complexity and weight, not to mention the fragility of the cells, themselves.