I don’t think he’s changed his tune at all since making the film, that’s the point. He was just being honest about his initial reservations with the script, and people on the internet (not understanding nuance, as usual) have misconstrued that into him hating the film and Rian Johnson too.
I don’t think he hates the film, he was deeply conflicted and troubled with what they’d done to his character. Having had it explained to him and then seeing it, he understands how it was required for the story. This doesn’t mean though that he doesn’t still “fundamentally disagree” with what was done with his character. But the movie is made and it’s out, he has to move on and still get along with his colleagues and the studio. He accepts what has come to pass and chooses to move on rather than fight a pointless battle. Such as will I when I tire of discussing the controversy that is TLJ.