Elimination Match

I had a cool idea to test on how people play and build or problem solve. What if there was a mode that had all the champs but when you died as your first pick it randomly selected a new one? First team to run out of champs loses? It'd force people to make crazy weird builds like All together to try to make themselves have a good chance as whoever they chose or got. The gamemode would change over time due to addition of new champs as well and it'd be rather unique to see how the teamcomp could switch from heavily AD to all tanks to AP burst and back to AD at random points.