I still think they would require the neg test even with proof of vaccine, at least for some period of time. Even really good existing vaccines are not 100% effective.
Case in point: a good friend of mine had all her vaccinations for pertussis [whooping cough] plus extra when she was in the military. As an adult she managed to get infected with it. It took a bit to get diagnosed as multiple MDs wouldn't believe a vaccinated adult could have it; took a pediatrician hearing her coughing to do the diagnosis, confirmed with testing
Her titres showed she had no immunity. They did her titres for other things she was vaccinated for and they are fine. For some reason the pertussis never "took"...
So even with a highly effective vaccine there will be some people it doesn't "take" for, others for whom it will provide some but not complete immunity (eg so they could still get sick, but won't get as sick as they would have without the vaccine, as is sometimes seen with the influenza vaccine), and then those who will be fully protected.
Then there is the issue of "how long does the vaccine last". In the early period they won't know beyond "some X months" just because it won't have existed long enough.
So I could see them through the first year or two or till the end of the declared pandemic period or something still requiring testing... [or as long as the port countries involved require it...]
And yep, definitely many benchmarks missing. Presumably deliberate so they don't lock themselves into something more onerous than CDC will impose.
SW