It appears that somebody does not know how to read award charts.

For pre-June15th and post-June 15th travel the mileage required for domestic US travel is not changing. "Saver Pass" is still 25K roundtrip in Y.

International J travel will also be dropping by 5,000 miles on most routes as of June 15th.

The OP strikes me as a false alarm to provide cover for Delta on their abject lack of "low" seats to anywhere.

CO/UA is on the verge of eliminating DL as a serious contender for the business of seasoned and frequent travellers. And Delta knows that.