A lot of people "declared" Greipel done only looking at the Tour and Suisse but probably he was only suffering for the contract feud with Lotto new manager, at the beginning of the season he was good in TDU and he was riding his best Sanremo ever (after the Poggio he was in the first positions of the group when he crashed due to Nibali bottle, something he was never able to do before), then he returned from the injury at Dunquerke and won the only sprint he contested before soloing to win the hilly/cobbled stage and won two stages at Belgium Tour.
Now after the announcement of his new team he returned to a very good level, I don't think it's only a coincidence, even if I think Fortuneo choice was a mistake, he will probably be forced to miss spring classics and a lot of WT races and I can't see an actual lead out looking at Fortuneo roster.