I don't know if it's different on the east coast but I have never met a single person whose gotten any severance. About the nicest I've seen from companies is them saying "we won't dispute your unemployment claim"
From big companies? Which ones? And my limited understanding of labor law is that Massachusetts has more regulation on this sort of thing than most states.
Read https://www.thelayoff.com and typically any big companies layoff discussion will mention the severance package being offered.
I never experienced mass layoffs, just a slow removal of employees. Either outright firing, but one at a time, or some aspect of the job was changed abruptly and in a manner that garunteed people would leave. Those positions then wouldn't be backfilled. It's not doable on a scale of 1000s but it was doable on a scale of 30-40