Why are people convinced the next GTA is coming out in five years time? The story for this is done. The Housers have probably moved onto the next GTA.
Rockstar are capable of getting the next GTA out in the next 2-3 years. But let’s blame shark cards and blah blah for some odd reason. There’s like a tiny portion of their staff who work on GTA online. Do you think the other thousands of staff are just sat marvelling at GTA online in a corner? Do you really think Rockstar are withholding games that will make them hundreds and possibly billions of dollars just so people can buy a few shark cards? No.
They had to build RDR 2 from the ground up as I doubt they could have used any assets from the last game as it was a developmental mess.
I think they won't release a new GTA for this generation. We can realistically expect these consoles to be there for the next 2, maybe 3 years and GTA5 is still selling very well and generating heavy income via online mode. There is little incentive for them to move on, and if RDR2 online mode is well received as well then there is no urgency to release anything.
I think this generation will basically go without a GTA game, with the outside chance of GTA6 being the goodbye game of generation (like 5 was for PS3 and 360).