It does not (necessarily) mean that 〜; I don't mean that 〜; It is not (true) that 〜; It is not the case that 〜 It doesn't necessarily mean he understood.
-> negates what one would generally conclude from the previous statements or situation =it does not (necessarily)mean that~; it does not (necessarily) follow that~
deeana
*わけではない sentences and their context (whether before or after) are often connected by conjunctions like が and しかし.
I read manga for practice, and this phrase appears frequently in some form or another. I see it frequently when there has been some form of a misunderstanding (そういう訳じゃない、よ!)
LittleFish
that might be the opposite of という訳で (for that reason) but also used for summing up meetings. See [wake]
dc
Also you can say, というわけではありません I feel わけではない is heavier maybe becuase it clearly denied with ない.