First of all there were no “phases” in OG Wrath. There were “patches.” Phases are a classic thing indicating when content will be released. We are currently playing the last patch of Wrath.
Secondly, features were released in phase 1 of classic expansions. That includes dual spec, cold weather flying tomes, equipment manager, BG queuing from your UI and so on. RDF is a feature that should have been released on launch along with all the others.
You’re welcome.