According to Dave Meltzer on a recent edition of The Wrestling Observer Newsletter, Ronda Rousey apparently wants Paul Heyman to be her manager in the WWE but there are issues with The McMahons that will likely prevent that from happening.
There is also an added issue wherein Rousey is being pushed as a major babyface, whereas Heyman’s role is more of a heel, even though WWE Universal Champion Brock Lesnar ended up being a babyface with Heyman representing him. This was apparently not how the WWE intended for things to turn out. Some do feel that the WWE fan base will eventually turn on Rousey.
Rousey is also in the WWE because the world outside of professional wrestling will see her as the biggest star the company has ever had and because she has had a strong drawing power with female fans. The Observer also noted that the limited data they have shows that the RAW viewership with men goes way up when Rousey is on but the female viewership does not share the same luxury.

Source: Wrestling Observer Newsletter