NoAI tag causes mobs with default handheld items to lose them

Using the "NoAI:1" when summoning mobs causes them to lose what they normally hold. For example, vindicators, skeletons, and zombie pigmen will no longer hold axes, bows, and swords respectively.

What I expected to happen was...:
NoAI:1 would simply cause the entity to not move

What actually happened was...:
Some held item data was nullified

Steps to Reproduce:
1. Summon a vindicator with the name "Johnny" and the tag NoAI:1
2. Do entitydata on it and set NoAI:0
3. It will attack everything it sees with its arm out without its normal axe

I'm sure NoAI is used for displaying mobs, and currently as a boolean it will be difficult to change functionality later, but a "fix" for the two kinds of people (one wants NoAI to be used as display, the other as functionality) would be to introduce NoAI:2 and have that keep the usual mob items (basically an enum instead of a boolean)