Too bad. I was hoping. A fantasy world version of Empires: Field of Glory was more what I was dreaming of. 
That's sort of Sovereignty (from Matrix). Which I've heard is a buggy mess, although I haven't played it personally enough to find out. It's an ambitious game, but it isn't exactly a sandbox because it doesn't have a random map (so far as I recall). I think in principle it compares well to FoGEmp.
There are plenty of fantasy sandbox 4x games now, and Matrix is going to work on remaking the original Master of Magic, so that's coming.
Fantasy General was always Panzer General, and that is NOT a sandbox game, NOR a version of FoGEmp (which the TW:Warhammer games fill pretty well). Matrix has plenty of WW2-ish Panzer General inheritors, including a direct remake, and including a version for freaking Wahammer40K (i.e. Armageddon). If FantGen2 is like that, there's a reason.