I considered doing it for Arma 3, I was playing about with an Arma 3 server some time ago and the models are much better for creating certain areas. I wouldn't just want to recreate it though, I would want to possibly continue the storyline. As there was a background to Epidemic.
I have got a few ideas but obviously it depends on how many people are still a fan or enjoyed the Epidemic mod. Right now zombie survival games/mods seem to be dying down in popularity so I would want to incorporate a new style. For example, the "Epoch" mod is obviously very well made and is a good mod BUT in my opinion it's sticking to it's own style and the Arma 3 maps right now are terrible for zombie survival.
So it's either create a new design based around the current maps (Which I've been thinking about) or find/build a new map for Epidemic. I would agree with Chernarus but I feel it's outdated now and not really big enough for an Arma 3 mod.
I'll keep working on some ideas, in 2 weeks I can get a server to mess around with. I was just curious if there are still people interested, if it goes ahead, that would want to try it out.