Let's face it: Kunos is a company and as such, it works to make some well-deserved money. The normal thing is that they want to have control over their new product to offer quality, not get into legal problems, etc, etc... and also, make a living. And perhaps that would leave out that AC EVO could be modded freely as it has been until now with AC...
For all this, my bet is that they will release a game that will surely be very similar in concept to Assetto Corsa Competizione..... That thing that AC EVO would be compatible with the original AC mods and require few resources and blah blah blah, is my daydream... but as I said, I don't think it will happen, so I will most likely stick with my old Assetto and its shortcomings, that gives me what I need.