Mike - as sure as I can be without actually seeing a document. It was explained to me that it is a multiemployer plan, it is for a bunch of union employers (small employers but several of them) and the 5500 says it is a multiemployer plan. But I don't actually KNOW...
I've seen documents give this option when choosing 1 year of eligibility. It will ask if you want employees to wait until the entire 12 months of the year is satisfied or make them eligible upon completion of the 1000 hours.
I would never intentionally choose the latter.
Just because it's legal doesn't make it sane.