The news about free GTA V on Epic Games Store has been published on the largest Polish gaming news portal, Gry-online.pl. Gry-online claims that they have a very credible source that they can't reveal.
Furthermore, free Grand Theft Auto V will be the Premium Edition of the game. The edition includes:
Grand Theft Auto V
Grand Theft Auto V Criminal Enterprise Starter Pack (Grand Theft Auto Online content valued at over GTA$10,000,000)
As always - if you claim the freebie before the deal expires, it will stay in your library forever.
Rumour: Free GTAV on Epic Games Store May 14th
Damn! If GTAV is free, Epic must have beg Rockstars to do this for Epic. But of course, The premium online edition can be bought for $13, it's perfectly reasonable to expect the game to be a limited time freebie or included in a humble monthly by now.
(Take this with a grind of salt)