Vindicator Easter egg doesn't work, when using a spawn egg renamed as "Johnny"

What I expected to happen was:
The Johnny easter egg to work with a vindicator spawn egg renamed as Johnny

What actually happened was:

The Johnny easter egg doesn't work if a Johnny spawn egg is used

Steps to Reproduce:
1. Rename a vindicator spawn egg Johnny
2. Spawn in a pig
3. Notice that the Johnny doesn't attack the pig

Device NVIDIA Shield Tablet K1

Other Notes: The renamed vindicator spawn egg Johnny works in the Java edition

Edit by 576874: Better description of the issue