This bug exists since the creation of spectator mode in Minecraft Bedrock 

While in Minecraft Java the void is infinite, but which kills players even in creative mode, Minecraft Bedrock has a floor that can be walked using creative mode without dying

However, this floor can be traversed using spectator mode, and if you switch back to creative mode again, the player ends up falling infinitely. 

One idea that could make players want to fall into the void to stop challenging is: teleport all entities that are in the void to a layer above the building height limit

So the highest MLG world record can be beaten 100% in survival mode using The End dimension!