I can't imagine EVO being anything other than an upgrade of the existing tank. I doubt they're going to buy an entire fleet of new model Leopard 2A6/7 equivalents just for an armor package. But yes, you always have to make sure.
Sorry if this is annoying but I found something that might be useful.
http://forum.soldf.com/topic/11317-leopard-3/page-2
Swedish military forum. No mention of the Strv 122B before 2004.
Google translate:
STRV 122B used by GU Bat P4 2004-2005
It was not so popular due to the turret bustle, but clearly the car I'd like to sit in if you drive on a mine.