In Bedrock Edition, the entity IDs for the Evoker and Vindicator are evocation_illager and vindicator, respectively. This is inconsistent with Java Edition, where the entity IDs for the Evoker and Vindicator are evoker and vindicator, respectively.
It should be noted that the entity behavior JSON files in the vanilla behavior pack have the filenames evocation_illager.json and vindicator.json, matching their entity IDs. The filename can be anything, though, and has no effect on the actual entity ID, which is declared in the minecraft:identifier component.
The entity IDs should be made consistent by changing evocation_illager to evoker to be consistent with Java Edition. The JSON filename should also be updated to match.
*EDIT 2018-08-07:* Updated report due to changes in both Java Edition and Bedrock.