Correct. The chicks are not sexed when they hatch, so its a mixed bag.
Funny story, when i went to buy chicks a couple months ago, the feedstore pointed at a bin (of what i now know are barred rocks) and said "These are straightrun", without telling me the breed. So i thought that was the name of a breed of chicken. When i went to another feedstore and they pointed at their bin of RIRs and said "These are straightrun", i was severely confused and just bought my chicks. Later i looked it up and realized that i am an idiot