訳(わけ)ではないIt doesn't mean that, It is not the case, It's not like

のはXの方だ emphatically states what is true or relevant, often in contrast with something else, e.g. 勝ったのは彼の方だ ('He was the one who won.') わけではない, by contrast, qualifies or softens a statement, e.g. 彼が勝ったわけではない ('It's not that he won.') One affirms directly; the other downplays or denies.

はずがない strongly rejects something as being true. わけではない denies an assumption while leaving room for nuance. For example, 雨が降るはずがない ('There's no way it will.') vs. 雨が降るわけではない ('It's not that it will rain.'), implying e.g. that the weather might be poor in other ways, etc.

Both わけではない and というわけではない express the idea of 'it doesn't mean that (A)' or 'it's not necessarily the case that (A)', but differ in usage and nuance. わけではない attaches directly to a verb or adjective phrase to deny a specific assumption or conclusion, while というわけではない uses the quoting particle と and often adds a nuance of clarification or softening of an implied statement.

Both とは限らない and わけではない challenge assumptions, but in different ways. わけではない denies a specific inference or interpretation, e.g. 'it's not the case that (A)', while とは限らない emphasizes exceptions, e.g. 'just because (A), it's not always (B)'.

Both というものでもない and わけではない express that something isn't necessarily true, but differ in tone. わけではない directly denies a potential assumption, while というものでもない has a more indirect or reflective nuance, often meaning 'it's not always necessarily the case that (A)'.

Both of these patterns with わけ express negation, but with different nuances. わけではない denies a possible interpretation or assumption, e.g. 'it's not the case that (A)', while わけがない is a stronger, categorical denial, meaning 'there's no way that (A)' or '(A) is impossible'.