The Codex does not say that you can have Raptors as a retinue. There's nothing stopping you having a squad of Raptors as one of your Fast Attack choices and keeping your Lord near them. However, if you want them all to be as a single HQ choice, you will need to have Chaos Veterans.(posted 9125 days ago)Personally, I think Raptors are better because of their "Fearsome Charge" and "Hit and Run" special rules, which make them near unstoppable in close combat (unless you charge then into a f*****ng Blood Angels death company!)
Hope this helps.