727 clutch pack question

When tearing down our 727 for inspection, we discovered a "wave" steel in the middle of the clutch pack.

My buddy that has rebuilt a handful of transmissions said that he's never seen that and that we should ask around about it.

Is that normal? Does the rebuild kits come with the wavy?

We usually see waves on other makes in a different location, like out by the pressure plate.

Any helps appreciated. Thanks. Eric