In my opinion, talking about women ‘withholding’ sex as a ‘punishment’ implies a certain level of expectation or entitlement, like men are entitled to have sex with women
No they are not entitled. But the poster specifically instructs people to withhold sex. Even if the woman wants to have sex. This could make sense if the woman was having sex with someone who opposes the ownership of their bodies. But if the man already holds their point of view, what is the point? For who are they not having sex? What is being achieved?
Sure thing. But that is not what OP was insinuating with his original argument.