I am all for everyone having personal privacy.
Not at all against him going after someone for violating his privacy.
I don’t think he can however get damages related to how the info does anything to him regarding his divorce. In a similar vein, criminals cannot sue people for exposing their crimes because of the negative consequences that follow they experience.
It would be even more interwsting if the state he resides in still has adultery on the books as a crime. It is in my state, its still a felony.
IANAL ...
But I believe that “it’s the truth” is an absolute defense against a charge of slander or libel.