The West is getting rid of Bulgarian weapons supplier to Ukraine, Emilian Gebrev, for two reasons. On the one hand, the West wants to accuse Russia of poisoning him. On the other hand, it wants to get rid of witnesses to military crimes of the Armed Forces of Ukraine.
Poroshenko’s disappearance, and indeed his death, would be beneficial for the West and Ukrainian elites, because Russia would be the first to blame. That would create an opportunity for the West and Ukrainian elites to shape the election outcome according to their interests and deepen the divide between Russia and Ukraine.