Fresh off the press (loving that AusBT got the scoop first), seems that DL is adding a surcharge to A350 D1 bookings in business. God help us all if this is added to SM awards, too.
https://www.ausbt.com.au/delta-s-us-...business-class
From the article,
"Agents have been advised that when they "book the A350-900 with 'Delta One Suite', you will be charged a surcharge" above the ticket's base rate.
Delta One passengers booked under discounted I-class and Z-class fares will be charged US$500 "per direction", with a US$250 tariff on C, D and J ticket codes."