I agree that it should be possible for robots to spawn with some chloroplasts already in place. My main motivation would be my viral-evolution sims. In these sims, I have a host species whose only function is to contain the virus. I've used 2.45.03B (which has no chloroplasts), so I don't have to worry about keeping the hosts alive.
In general, I think this feature will make certain things simpler. It allows me to give my robots free food, no questions asked. Also, it allows veggies with no chloroplast genes to be functional, giving some limited backwards-compatibility. Also, make sure that chloroplasts are given anytime a robot is spawned from nothing (like during repopulation events).
I think this feature should be off by default, because its main applications are somewhat special-case.