The ERISA definition of a church plan is a plan established and maintained for "the employees of a church or a convention or association of churches.” 

Have the courts taken too narrow a view of church?  Are the plaintiffs really church employees?  Out of curiosity, I checked out one of the defendants' websites ... Dignity Health in SF.  Here's what I found.  "Dignity Health is a not-for-profit organization, rooted in the Catholic tradition, but is not an official ministry of the Catholic Church."  So Dignity wants to treat hospital employees as employees of a church ... but one that doesn't have a ministry?

I had almost forgotten something from my decades in the employee benefit field.  More than once (a lot more), notices of certain legal requirements delivered to organizations like these elicited a response that amounted to, "But those rules are for others, not us.  After all, we're doing God's work."