Does disproportionally mean unequally?

In order to understand what disproportionately means in such a context, we have to ask what would it be like for men and women (or any other groups) to be oppressed proportionately. As soon as we formulate that question we see that it is incomplete: proportionately to what? It is possible, for example, for the oppression of different groups in a society to be proportional to their number in the population, but it is also possible for it to be proportional to some other characteristic. What that characteristic is needs to be either stated explicitly or clearly implied by the context.

If (but only if) the relevant groups are equal with respect to that characteristic, then to oppress them proportionately is to oppress them equally. For example, the number of men and women is roughly equal, so, if they were oppressed proportionately to their number, they would be oppressed equally.

Now, if one says that they are oppressed disproportionately, one is denying that they are oppressed proportionately. To understand what is being denied it needs to be either stated explicitly or clearly implied by the context what the characteristic is to which the oppression is disproportional. The quoted sentence, taken apart from any context, does not tell us that. We thus, strictly speaking, do not know what was meant by it.

It is possible that the person who uttered that sentence had in mind some characteristic in respect of which men and women are obviously equal. If so, saying that they are oppressed disproportionately to that characteristic amounts to the same thing as saying that they are oppressed unequally. It is, however, also possible that the context will reveal that the person had something different in mind.

If you had two groups of kids, one group in green shirts consisting of 20 kids, and another group in yellow shirts consisting of 50 kids, and you gave the first group 40 pieces of candy and the second group 100 pieces, you would have done a proportionate distribution of the goodies, as there would be two pieces of candy for each kid, regardless of the group they were in.

But if you gave the first group 100 pieces and also gave the second group 100 pieces then the distribution would have been disproportionate, since the numbers distributed were not in proportion to the sizes of the groups.

The quoted sentence is a little puzzling since the number of men and women is roughly equal, but it suggests that one group has been oppressed more than the other.

As suggested in the first answer, if something is disproportional, it suggests that a quality, quantity, or trait in one distinct grouping or collective is out of proportion compared to another.... but the phrase/word is used primarily where/when it is unnaturally so.

The fact that Women give birth to more children than men is extremely disproportional.

The responsibilities of male and female parents will always be disproportional as a result ... even if they - all taken into account - are equal.

The term is generally used in the negative when some aspect is out of balance.

eg: "Our son Jamie spends a disproportionate amount of his time and energy on his video games"

This is a negative expression if said 'Jamie' ought to be spending more time either on his school homework, his job, his family etc ....

.... but if said 'Jamie' is a video games designer, then it may be positive ... or perhaps suggesting obsession.

It's all about balance/imbalance.