You and a bunch of others in the thread are starting from the presumption that these people were very well compensated. But we don't have to make _only_ assumptions, you can look up some perhaps stale and perhaps biased self-reported numbers. The most convenient of these to access for recruiters at twitter (who seem to be the ones impacted) guess a median compensation of 137K, with around 94k of that as base. I think that base is just about at median income for SF for a single earner (though of course they could live elsewhere).
Other people in this thread are talking about what I understand to be hypothetical engineers with 400k compensation, and it sounds like that doesn't describe this situation.
Lots of HR roles in there which is usually where recruiters are positioned. Unless you are saying all twitter recruiters on payroll are US citizens or permanent residents. Be sure to search all years.
Even selecting all years, I see no evidence of Twitter having H1B recruiters, and I don't think this is surprising. Companies are prepared to go through the process (and can make a credible claim of needing it) only for some roles.
Other people in this thread are talking about what I understand to be hypothetical engineers with 400k compensation, and it sounds like that doesn't describe this situation.
https://www.glassdoor.com/Salary/Twitter-Recruiter-Salaries-... https://sfmohcd.org/sites/default/files/Documents/MOH/BMR%20...