My guess is no. Concrete fails under tension and with the irregular and natural assembly process the structure probably would have issues with tension and all the extra weight. The cost of filling each bamboo void would also make it costly and less renewable. My gut feeling.
Maybe, but the real reason you don’t fill bamboo isn’t entirely hollow. It’s just got individual hollow segments.
Bamboo is already incredibly strong as it is. The main concerns seem not to be about bamboo’s strength, but rather it’s susceptibility to insect attacks.