They considered between UE4 and in-house graphics engine. It's obvious that UE4 allows using their own physics, otherwise they wouldn't have selected it. When their expertise is in simulation physics, are you actually dumb enough to think they are willing to throw that outta window, in exchange of shiny graphics?
If anything, it will have more advanced simulation, able to focus on just one type of cars.
"Assetto Corsa Competizione is designed to faithfully recreate the performance and the driving experience of real Blancpain GT Series cars through a sophisticated mathematical model that accurately replicates tyre grip, aerodynamic impact, engine parameters, suspensions and electronics systems that determine vehicle balance, as well as the influence of mechanical damage on the car's drivability."
"...reaching a new standard in terms of driving realism and immersion, thanks to its further improved tyre and aerodynamic models."
And not biggest fan on GT3 cars, but still hyped AF. Instabuy. All the other factors like improved sound, multiplayer, visuals and dynamic track makes it a nobrainer.
And new year/season is probably DLCs. Not a new game. I'm seeing this will be updated and getting content many years from now, just like AC was.
Mod support is a question mark.
But if all LS tracks and real cars are in the game, what would modders do.