It may be predictable with code that simulates what ED_Alloc() engine function does here:
https://github.com/dreamstalker/rehl..._edict.cpp#L48
I don't think it's possible to do it from an AMXX plugin though. As far as I know, AMXX doesn't offer any natives that deal with edicts directly, so it probably has to be written within a module.
Why do you even want to predict the id? I don't see how is that useful.