According to Le Roof, Rykros was created as a type of warning system. Every 1,000 years when the seal on the Profound Darkness weakened, Rykros would return to Algo.
Do you think Rykros was really effective for this purpose? It was cloaked in an invisible barrier, so no one in the system had been aware of it's return until the PSIV heroes went there. It seems that if the planet weren't cloaked, people might have been more aware of what was happening.