While I understand your point, I think a bigger theme of One Piece than friendship has been letting the people you love go if it means they can follow their dreams. This was hammered in with Ussop when Kaya lied about not wanting him to leave, Sanji when the cooks pretended to hate his food so he'd give up his sense of responsibility to them, Franky when the Franky family stole his speedo to force him to go to the Sunny, and Jinbei when his crew gave their blessing (though this is the one case where he actively asked for it). Arguably Chopper to an extent as well. Law can't possibly reach laugh tale with his crew. I don't think he will simply decide to abandon them, but them actively letting him go would be very in line with the series.