There's really no reason for Facebook to make this rule specific to Ukraine. If your country has been invaded by a foreign army which is violently attacking civ

There's really no reason for Facebook to make this rule specific to Ukraine. If your country has been invaded by a foreign army which is violently attacking civilians with tanks and bombs, it's perfectly reasonable to cheer for the deaths of the invading soldiers. This is basically analogous to the concept of self-defense. Actually—would it be against Facebook's rules to post about how you fought off someone who tried to break into your house to kill you?