Lappi has apparently been given the future of Citroen. Bide his time, develop and he'll be the man who keeps Citroen in the series post Ogier.
He's quite disheartened by how dominant Tanak has been in the same car, with a year's less experience in the Yaris. Im sure there's a few other reasons on top of that he's not totally happy at Toyota, but it is what it is. A big pay rise is maybe enough at his age to leave one team for another and who can blame him? Money talks