No the game does not treat gold and high gold the same. Matchmaking still uses the underlying 'ELO/Rating' for its calculations. The previous system compared to now is no different except for how your threat is displayed to you.
Matt Scott has better stuff to do than to reply to a forum thread that should have been a support ticket from the get go. Plus if he or another staff/mod did reply, he would just tell you to make a support ticket too.
The bourgeoisie stated that you are no longer allowed to benefit off the working man with your surveys for petty levels of G1C. You must now become a productive member of society by giving back to your community through social duties such as work.
Adding Diamond/Plat threat does not change how the threat system works. The threat colours are graphical only and not representations of your actual threat level.
Also you forgot tanks, and bikes, and choppers, and racing district.
Creation of a new car from scratch to implementation takes over a month.
Plus within a few months you'll just get an over saturation of uneeded vehicles.