There is a very basis here for invoking “rule of law” where:
1) we’re talking about discretionary grants being made out of taxpayer dollars;
2) congress has delegated authority to make the grants and to the executive, including determining indirects; and
3) the executive action is being used to save money.
It’s also “the rule of law” in some sense when NIMBYs sue to keep a Ronald Mcdonald House from being built in their posh neighborhood, but that doesn’t mean we need to lionize it on that basis, or preemptively surrender to efforts to invoke the law to block reform. The universities can afford expensive lawyers with their 59% indirects, let those lawyers worry about it.