Yes, and in other countries, people also get notice of layoffs, get real vacations. They can afford to give longer notice because it’s reciprocated by the culture.
But the post claimed “(Especially if you work in an “at will” state like California.)” There’s no such thing as “an ‘at will’ state like California”. The entire USA is an “at will” state.
In the US, the recommendation of this post is… naive.