So uhh I will update on this but in an attempt to chase a particularly nasty Desync problem, I've found that this model works fine when downloaded and on your own PC; however when you host the map online and someone else downloads, the effect does not show up when triggered.
I'm reimporting the file now but this is pretty stupid. I don't think this is the cause of the desync.
UPDATE :
I reimported the file; it now works on battlenet. I don't know how it ended up breaking, maybe with a reforged patch or something. The model is definitely safe, but be careful with imports in general I guess.