No, Opus Dei doesn't hand down from on high any political or professional instructions to any of its members, priests, unmarried, members, or cooperators, ever. 

The only thing it hands down is the formal teaching of the Church (not its own) [very well delivered] and a certain demanding spirituality....which in essence is "live out your faith, fully and completely, right where God put you, but as a child of God."

There is an enormous focus on "freedom and responsibility".  Humans grow the most when we fully and properly exercise our freedom.  

What a member of Opus Dei does in his or her profession is NEVER reviewed/approved by his or her spiritual director or by the Director of a Center, much less OP in Rome.  It's a silly assertion.  

SPXX won't be "joining" Opus Dei in any sense.   SSPX may begin operating as a personal prelature, but that's likely saying that a newly forming diocese in Madagascar will be joining the Diocese of Scranton!!   It's simply a structure of operating.