There's the legal world and then there's the world of custom and ethics. They don't always diverge, but in my experience they do.
At least over the last 25 years in the tech spaces I've been part of, I rarely hear of people being dismissed/let go quickly. #anecdata
is this sarcasm? tech industry has some of the worst layoffs ever. i have personally seen several different employers notify employees day of firing they no longer have a job