The election in Turkey is over; he no longer needs to placate Russia for resources or his conservative, religious electoral base. This action tells me one of two things (but I'm just an internet know it all): 1. Erdogan has enough economic leverage over Russia that he can do what he wants and they'll still extend the grain deal next month or 2. He has been notified that the grain deal will not be renewed under any circumstances and is just trying to get back into western good graces.