I noticed these types of claiming events at Oaklawn earlier this year, but now they have sprung up at Santa Anita as well.
Waiver Claiming is a claiming race where horses that were claimed 180 days or more ago can enter for the claiming price of their last start and not have to race for a tag in their initial start back.
A couple of things that I've noticed. The description shows on my HTML report, but not in the PP's that I generate using BRIS's PP Generator.
Also, it appears that they are designated as a "C" in the HTML report.
I can see this taking off for protection of the owners and wondered if you've talked to BRIS regarding a different designation such as "WC" similar to the "AO" designator.