The plaintiffs in the ICWA suit out of the federal court in Texas asked for time to file an amended complaint. It’s here. Case page is here.
Additional state parties are Indiana and Louisiana. Additional children involved are from White Earth and Ysleta del sur Pueblo.
A word of warning–I swore at the complaint by paragraph 4.
ETA: This interesting (related?) article out of Indiana: DCS Director Resigns
Turtle Talk 
If the states would make appropriate placements from the beginning and if these foster parents were explicitly told up front that they have no reasonable expectation of adoption, these crazy lawsuits would either go away or be pretty easy to handle.
The placement point is well taken, but unfortunately foster parents ARE told that explicitly and still bring suits like this (see e.g. Alexandria P.).
Why do they have standing?
I assume that will be brought up in future briefing. In California courts, of course, foster parents can get de facto parent status, and then have standing.