Zirconium
The Journey II is a Zirconium van returning from earlier GTA games. Rockstar first showed it in an official screenshot (Grassrivers 02).
Bison
The Bison is a Bravado van returning from earlier GTA games.
Bobcat XL
The Bobcat XL is a Vapid van returning from earlier GTA games.
Boxville
First shown: Official Screenshot: Ambrosia 02
Burrito
First shown: Trailer 1 (1:03)