You can still put stuff in the back, but it cannot carry passengers behindExternal link →
This is a funny one! Believe it or not, this is a side-effect of some of the additional work we needed to do to test the new networking model in just Firefight: King of the Hill. We could've done a blanket flip of the switch for the entire game, but that'd be wild without testing at scale beforehand. So, we took some extra steps to ensure a safer approach in just FF KOTH. During this process, some of the wires for the Razorback got crossed - resulting in this silly looking puma.
While it's pretty amusing to see in-game, it is not a future vehicle, just a good example of why we didn't just flip things over all at once.