A earlier press release absolutely had "Early July" as the month for the start of the boxed meals. Quite a few of the blogs mentioned it as well as Delta themselves

https://news.delta.com/coca-cola-min...s-return-delta

"In early June, customers flying in Delta One or First Class on select domestic coast-to-coast flights will see hot food options return, and First Class customers on other key U.S. routes will enjoy fresh boxed meals beginning in early July."