Every recent Codemasters game gets a Trial version, it's known to bring new players in, some of which go all the way and buy the game.
These Trial versions are the full game download, but with the majority of the game locked off until purchase. The upshot of this though is that the Trial never expires and any progress you make carries over to the full game.
Trial version also gets all the performance patches and stability improvements of full game.
The reason it's not available at launch is because it takes up development resources, and full game takes priority during launch.
Last edited: Nov 26, 2020