Severance is compensation. Compensation is a contracts issue, done at market terms. His first point captures all the ethical concerns required to fairly negotiate contracts. Near as I can tell, formal severance guarantees are also rare, meaning that you're often negotiating for it against other candidates who won't demand it.
Employees aren't intrinsically entitled to severance pay, as some sort of natural law of business.
Another way to rebut the idea that severance is an ethical requirement is to say that the same ethics would demand giving engineers raises, or paying them the maximum amount the business can bear paying. That's sometimes true, but often not, depending on the role of engineering in the company.
I take it more to be a point about the size of the severance compensation relative to the company's resources. IE, don't claim poverty (and thus no severance) when you've been funded. Basically a variation on "Don't lie to your employees about money".
Employees aren't intrinsically entitled to severance pay, as some sort of natural law of business.
Another way to rebut the idea that severance is an ethical requirement is to say that the same ethics would demand giving engineers raises, or paying them the maximum amount the business can bear paying. That's sometimes true, but often not, depending on the role of engineering in the company.