People (from the committee of experts appointed as national body representatives or invited experts) submit proposals which is essentially merge requests to make changes to the C++ draft. A proposal, by the way of it's changes, can either add a feature to C++ or remove features from C++ (kind of like deleted code).
In each C++ meeting, they have a vote for each proposal in the meeting and decide whether that proposal is allowed to act on the C++, thereby determining if the features gets in the draft (if the proposal was proposing a feature) or if the features is kicked out of the draft (if the proposal was advocating for removal of a feature).
Once a proposal has been voted in the draft, only another proposal can remove that feature from the draft.
Every 3 years, they seal the current state of the draft into a standard and send it for voting to the official ISO C++ committee of national bodies (different from committee of experts we mentioned above). And I think each national body has a veto. (that is the vote has to be unanimous, but not sure here).
At this point, first the National bodies can make comments where they can threaten to veto the standard if their comment is not looked at. Then, the committee of experts can either respond to the comment or follow the comment or do whatever.
The official committee (essentially national body members) then votes and can only approve or reject the standard in the whole. So, if they reject of example C++ next now, there will be no C++26.
The whole process from sealing to actual voting takes around a year or so. In the mean time the committee of experts starts working on the next c++ standard from the sealed state forward without waiting for the committee to ratify the current one.
What Bjarne is doing is that he was threatening to get a national body to veto the proposal so that there is no C++26 at all. So, his point was, either accept his paper as it is (which calls for removal of contracts from the C++ draft before it goes to committee of national bodies), or he probably gets US or Denmark or some NB (not sure which) to vote no on the C++ standard (when it eventually goes to the committee of national bodies with the contracts in it, kind of like throwing baby with the bathwater).