I don't like renaming existing compiles of maps, because it can cause some internal BSP structures to have strange behavior. When a map is compiled, a few things are tied to the BSP name itself. I've seen texture issues, like them going missing, corrupt normals, broken specular maps, etc. The cubemaps in particular also tend to get screwed up, because the Source engine treats a BSP like a folder in a file system when reading internally stored resources. So if the cubemaps were originally zm_fubar_v4 and you rename it to zm_fubar_v5, the engine is still looking for them in the old directory and won't find them, resulting in default cubemaps everywhere.
These issues may have not cropped up in this map, because it doesn't use cubemaps or custom textures, but I like to be on the safe side.
I would be concerned about differing BSP versions, but this map is 16 years old, and very obscure. There aren't going to be many people today that still have it. And those that do are probably going to know how to delete their local copy of the map and download it. Since you had version 2 on for so long, I don't think it will be much of an issue.