I was touring the train tracks in RDR2, when southwest of Cotorra Springs, down a dangerous hill, I spotted an entire train crashed under the bridge (it is the location of a gold bar). The scene reminded me of a GTA V mission, in which Trevor gets on a train using a motorcycle, and crashes the train on a similar bridge to steal, also gold, a Mayan statuette and give it to Martín Madrazo. Being 5 years after GTA V, RDR2 is likely to reference the mission.