That’s unfortunate.
Technically this hasn’t been approved by the General Assembly yet, and then individual countries would need to ratify it. But press coverage suggest it’s a done deal.
For the treaty to go into force, 40 nations have to ratify it.
In many places, ratifying a treaty requires parliament approval, so it’s not going to be quick. Talk to your representative once this treaty comes up in your parliement’s agenda.
These 5% of negative reviews probably has nothing to do with you. There’s always a small amount of people unhappy for random or unrelated reasons (broke up with boy/girlfriend, car broke, etc) and who would write negative reviews no matter what. It’s possible they cannot dissociate the course from other things happening in their life. They just happened to be unhappy at that time, and felt like leaving a nasty review.