https://wow.gamepedia.com/Macro_conditionals
Neither "nocooldown" or "nochanneling" are valid conditionals. Macros cannot make smart decisions for you (ie: do X if X spell is ready/on cd/etc).
Your best bet is to probably make 2 gear sets (1 with spirit gear & 1 normal gear). Then make a button in WeakAuras to show on your screen when evocation is off cooldown and make it do all the swapping, casting, etc.