There is a glitch where you can jump from desert to the new spawn, and spawn is a no pvp area, so zombies can not hit humans same with humans can not hit zombies, so basically its impossible for zombies to win. You might want to move spawn away. I would suggest not do anything with desert. Only move one of them away from each other. Sincerely kegmister.
Well the only way they could fix this, is probably moving it, which they might do, Or they'll add iron bars along the bedrock to stop people going there, Remember Hijacked and Winter, the bars are gone now, so I think that they might do that, (maybe)