Article 71 of the treaty provides that a contracting state may denounce the convention by written notice of six months. The denunciation takes effect six months after the receipt of such notice.
You're right that if there were a dispute under way pursuant to the convention, there's been a lot of discussion in the legal community about what the implications of that would be.
There has not been any final resolution of the matter. If there were a tribunal already formed—let's say, in the case involving Bolivia—that tribunal would make a ruling, and then Bolivia might seek annulment proceedings, but we don't know what the resolution of that would be.