LinkedIn should set up a code of practice that bans this. Rescind offers? Then you can't advertise on LinkedIn for the next 5 years, and we won't host your job posts either. That would change the calculations at these companies and make the jobs marketplace better, at little cost to LinkedIn.
Let's imagine the issue i mentioned above doesn't exist. Linkedin figured out a perfect way to figure out and filter out companies that rescinded offers. If that became a problem for companies, then a company would just hire someone and then lay them off immediately. Same result, but larger administrative/accounting overhead, so no severences for rescinded people, most likely. How would Linkedin track that? What's the time period cutoff for which laying someone off/firing them is considered "just a loophole around rescinding an offer"? A week? A month? How will you be able tell the difference between an instance of someone being fired within a short period of time after starting as a loophole around rescinding an offer vs. someone genuinely being fired within a month for whatever legitimate reason?
Imo i dont see how the current situation with coinbase/meta is a reason for such a major outrage. I could have understood it, if they were habitually known for rescinding offers as a part of their regular practice. But they don't, they all did it exactly once, at the same time, due to a very legitimate reason of a strong economic downturn affecting their survival/livelihood very badly. Imagine your spouse was having serious health problems, and you just found out you will need to take care of them for a year, right after you just accepted an offer from a company a few days ago. I think it is more than reasonable for that person to rescind their offer and tell the company they have something that's more important and that matters to their survival.
And that's not even mentioning that coinbase is paying severance worth 2 months of work (as well as provides job search assistance services, whatever that means) to those whose offers they rescinded. So those people essentially are paid for 2 months of job searching. Still sucks to deal with job search, don't get me wrong. But that severance package wasn't expected and feels pretty fair.