You'll see a PC announcement within 3 months of GTAV's console release. The make boat loads of money off of the console release, satisfying their shareholders, and then one sales start dipping they'll begin the hype machine for the PC release and possible XB1/PS4 versions.
It sucks, but this franchise makes a lot of people a lot of money each time it releases, and they're only trying to make as much as they can. This has been the pattern of console & PC GTA releases since GTAIII.