DL will do this when they want to unilaterally raise prices on international J.
The current D1 fare becomes the Basic fare with fewer perks and the Main D1 fare increases.
I can see them releasing this before ATL D1 lounge is built out. It will just cause anyone originating or connecting in ATL to more strongly choose the basic fare, which will still not be a loss to DL at all.
DL will make their "basic" one little bit less onerous than UA and then call it the most Premium Basic J experience.