No. Most people don't know what a sandbox really is. People here still call the original EQ a sandbox which is wrong.
Themepark is WOW. Each zone has a level range, you get pushed from zone to zone as you level. EQ did it with mob cons. WOW did it with quest hand holding. (Games like TSW, AOC, Rift, SWTOR, Wildstar, GW2 etc. are all themeparks)
Sandbox is more like UO or EVE (or if you want to get nerdy, ATiTD). Games like Darkfall have some sandbox features in them with building cities and towns and skill building. Essentially a Sandbox is a game that gives you tools to do things, and then says go do them and isn't just a level/gear based treadmill game.
If the majority of a game's gameplay is Kill MOB -> Gain Loot/XP -> Gain Level and repeat it's most likely a themepark.