This is a Schrodinger's cat question. They could or they could not. It depends on how they have personally handled and processed their childhood situation with the alcoholic parent, and on the maturity of their mind. It can be said that sometimes a child of an alcoholic might be repressed in terms of personality growth and mental maturity, but these could be rare cases. It's not generalise about others.
It can be a case where children of alcoholics seek out other alcoholics because to them that's the model of what a relationship is, which they've seen as an observer to their parents. However, this is an individual choice. Being adults, they should be able to rationalise and understand the implications of their actions, and thus decide to get out of the vicious cycle.
We are all, almost universally, attracted to people with whom we can have relationships that are similar to those we know from growing up – the ones we had with our parents. The reason we get along with some people immediately – the ones we “click” with – is because the way they relate to us is familiar. We know how to interact, what’s expected, what’s normal, etc. Then we often have the same relationship difficulties with our spouses as we had with our parents because of it. Adult children of alcoholics are often attracted to unstable people because for them, that’s what feels familiar.