From an agency representative (on May 29th):
What we were told today, from reputable sources in Ethiopia, was that the investigation will be complete and they will begin hearing cases again of abandoned kids by the end of June. That is really all I know. I guess that is at least a timeline. I am not saying that by the end of June doesn't mean it couldn't be earlier than end of June, but I really don't know that is just what we were told. They will get these cases on the docket through before courts close, I am sure.
Note: At least 2 other agencies have also been hinting about a possible resolution by the end of June.
*Edited to remove the name of the agency. I like to include agency names so people know where the information is coming from (and that it's coming from a reputable source--an adoption agency licensed in Ethiopia), but in this case I've decided to remove it. The person providing the information didn't tell me themselves which agency it was, and I'd like to respect their anonymity.