I would assume yes - unless those states have expressly denounced the treaty (like Denmark, Germany, and the Netherlands seem to have), or their modern successor has not affirmed the treaty.

In one sense, the UN has 'affirmed' it by amending it without completely rejecting it, and it remains among the multi-lateral treaties deposited with the UN.

Generally speaking, unless there is some kind of 'sunset' clause in a treaty, or a term which states conditions that the treaty ceases to be effective and these are met, they continue to exist.