Wouldn't the individuals who issued the chargebacks do so irrespective of what happens with their car in-game? It's not like they can use it either way.
Also, you're saying that you feel the supercars were removed from dealerships to encourage player-to-player transaction as opposed to buying from an NPC?
I haven't been on in like 6 weeks and when I last read the rules cars purchased with credits weren't to be re-sold, iirc.
What I am saying is if Player X was banned and does not submit an appeal for, let's say a week, then they clearly aren't that interested in returning.
However, if Player X does submit an appeal their assets are to be frozen pending the outcome of the (potentially months-long) appeal process.