After the revolutionary update, inactive teams were automatically relegated in PRO, but i read in the forum that it was enough ask that a team will be move in Elite by DEV.
However I would probably "swim against the tide": there is a common habit among many that used multiple CD, exit and re-enter a championship during the break to fix the reset with the result that at the first race we all have "almost the same" cars, while it would be more "fun", in my opinion, to have slightly different cars in order to decrease the "luck in qualifying" effect.
if at each championship change, you ended up relegated to PRO automatically, this practice would be avoided.
another suggestion would be to be able to enter/exit an ELITE championship only during the break and not during the season; also for inactive palyers.
these are just suggestions to think about.