It does not necessarily mean that...; used to deny or qualify a statement (softens a categorical negative).
嫌いなわけではありませんが、今はあまり食べたくないです。
It's not that I dislike it, but I don't really want to eat it right now.
忙しいから行けないわけではありません。行きたくないだけです。
It's not that I can't go because I'm busy. I just don't want to go.
彼が嘘をついているわけではありません。ただ話を間違えているだけかもしれません。
It's not that he's lying. He might just be mistaken about the details.
高いからといって必ずしも品質が良いわけではありません。
Just because something is expensive doesn't necessarily mean it is of good quality.