The Star Wars Black Series 3 pack of Astromech droids was originally announced and displayed at Toy Fair 2018 and it was stated this would be an Amazon exclusive.
While a small amount have come through the far east, we haven't had any details of a widespread release - until now, when the Amazon holding page went up for this set. There is no price or release date as yet, but you can bookmark now and add to your list so you are notified when the set goes up for order.
The pack contains R2-X2, R5-D8 and a weathered R2-D2. These three droids all took part in the Battle of Yavin with R5-D8 flying with Jek Porkins and R2-X2 with Theron Nett (Red 10). The boxset is being called the Red Squadron Droid Set