That would kill the idea why matchmaker is required in the firstplace. How to verify, if the code is correct if offline? This would lead to quick .... and ISI would lose money = ISI would not be able to focus so much on rFactor 2 development = we would not get so much extra content = bad.
I am sure this will not happen, matchmaker is and will be the only possibility to play multiplayer games. (99.9253%)