I just got a reply from the USTA. From what I was told... If you have an Exclusive- Mixed, Self-rate or Tournament rating. Meaning a M, S or a T next to your rating and you have been playing exclusively Mixed or Tournaments as a M, S or T, to play regular Men's or Women's you will have to self-rate to play. However, if you exclusively play Men's or Women's, the USTA does not take into account your matches played on a Mixed team per Rule:
https://www.usta.com/Adult-Tennis/USTA-League/frequently_asked_questions/#12941
Does a dynamic calculation apply to Mixed League play?
Yes, for players who participate exclusively in the Mixed Division. Mixed results will not be included in year-end rating calculations for those who play at least 3 matches in any Adult Division.
Can I use my mixed exclusive rating to play in other divisions?
A mixed exclusive (M) player must self-rate in order to join the Adult Division. Mixed exclusive is a minimum NTRP start level only. A mixed exclusive rating is not supported by any NTRP dynamic disqualification calculation data and is subject to NTRP grievance.