Block Party is the intellectual property of Hypixel (I think that's what server it's on), so if a server decided to make a knock-off, he would have every right to take legal action. I highly doubt this would happen, but Cubecraft does have a pretty strict policy of not taking ideas from other servers. Everything they do is either 100% original (their plugins are 100% the work of the devs, as far as I know) or so mainstream that no one can call claims on it (like Skywars or Survival Games). It sounds like a fun idea, but it'd be best to come up with an original game that's never been done before.