Evokers don't spawn in raids

Put the summary of the bug you're having here

What I expected to happen was...:
Evoker would spawn in raids

What actually happened was...:
According to the wiki (now I know this isn't the most reliable source, so if this is completly incorrect please let me know) Evokers should spawn in raids, but no matter the bad omen level I had, I couldn't find a single evoker. I used commands to get bad omen, and even tried to find actual patrol leaders and kill them to get the effect and then enter a village, I could find every other illager (other than illusioner) in the raid. Again please correct me if this is a bug or not!

Steps to Reproduce:
1. Kill patrol leader / Use /effect to obtain bad omen
2. Enter a Village
3. Woala!