I got the impression in TFA that Leia had been shut out of the political process somewhere in those three decades. (I think someone said the novelization suggested the information about her true father was used against her?) Would that also cause the New Republic leadership to distance itself from Luke and the attempt to bring back the Jedi?
That could also factor in Luke’s decisions.
In Bloodline, a recording Bail made to explain Leia’s parentage to her in case of his death is found, and one of her political opponents plays it for the entire Senate, destroying her political career.
This is also how Ben learns about his grandfather, as Leia and Han hadn’t told him yet. (He’s off training with Luke in the book, so we don’t see his reaction to the news.)