I think it would be best to ask a moderator about that, but as far as I know they're planning on adding a fourth minigame, however, a poll has been done (https://mccentral.org/community/threads/4th-minigame-poll.152854/) in which Murder Mayhem clearly was the game least wanted to be added. So I wouldn't count on it.
im not too sure if those minigames are coming back or not but i forsure hope so. murder mayhem, cakewars, etc. i miss them and the community
There probably won't be another minigame purely based off the fact that the current ones get no players (excluding ctf) and when the revamp was first added, nobody would say anything positive about it so that made the owners apparently just stop because of that so its unlikely that another one will be added unless minigames become more popular
The revamp fixed most major glitches, added maps which are mostly better than the ones we had, made the gameplay more fair for rookies, finally complied with the EULA. Despite all these positive changes, people left because "oOh I LoSt tHE lEveLs I wOrKEd YeArS fOR". You are not worth your level if it originates from a distant past which is no longer relevant. The revamp killed the server because 95 % of players won't even read threads like this and are too stupid to realize shampoo contains soap. Yes, very few minigame players are still here, but they are almost all nice, friendly players who actually care about the game and are actively trying to improve the server. You can't fix a broken car by complaining about it being broken. You can fix it by either buying the parts and repairing it, or by seeking help from friends or professionals. Take that message home when you complain. The owners, admins or moderators didn't kill the server, they only created a climate which facilitated the dieoff of the server. In the end the people who left killed the server.