An extreme and inaccurate statement. The US is still party to NATO Article 5, meaning the blood of our young people is pledged to be shed to defend, say, Estonia. That has not changed.
What has changed is the US has become more realistic and up front about the limitations of its reduced military. It’s not healthy, for the US /or/ Europe, to indulge the imperial fantasy that US forces in Europe (token deployments in Germany and Poland) are sufficient to defend against Russian attack.
Trump is not the first US president to push Europe to do more of precisely what it is doing here (spend its own money on defense). Being clear about limits is what a reliable ally does.
Europe ordering an Airbus AWACS instead of Boeing now that the US stopped subsidizing them is not surprising nor does it mean the sky is falling.