In this new culture of pseudo science, anything that causes more greenhouse gases can be linked to worsening global warming. Anything that causes less greenhouse gases can be linked to reducing global warming.
One day maybe they will be clever enough to figure out why the South Pole keeps growing colder, as it has done for the last thirty years. Maybe the penguins are generating less CO2.
But, to address the topic, cattle are generally grown on land that is not suitable for agriculture. They eat grass, grass takes carbon from the atmosphere. Growing cattle is another way of sequestering carbon from the atmosphere. I think the story about eating less meat reduces global warming, truly belongs in the archives of the greatest of Junk Science. But if you really believe that CO2 in the atmosphere is causing global warming, the whole story is not told about the role that herbivores play in the carbon cycle. And as far as N2O goes, their is vastly more N2O used in commercial agriculture than cattle production.