There's no "old normal" and "new normal", the world is somehow different on every next day due to a number of never-stopping processes. But, as for the "normal" of international travel, which I define as the ability to move between countries without quarantine or any other significant restrictions - I think that next summer will already be somewhat better than this one, with a tendency to go back to something close to what we used to know during the course of 2022-2023. At least in the Western world.
Why? Due to a combination of factors. Advancement in medicine, vaccination of the most vulnerable groups (hopefully as early as Q2 2021 for Europe), cheap and easy to deploy tests which can quickly isolate infected community members and curb further spread. And also the natural course of the pandemic. Even if the virus does not go away completely, it will be eventually managed to a point where it's no longer an overriding concern for any daily activity, including travel. Humankind had managed this a number of times before, including incidences of far more dangerous diseases during times of far less advanced medicine. I see no reason why this time it will be different.