Been there done that. The last company I worked for was always shedding workers. When I started there we had four thousand or so then there was a contract change and then we had sixteen hundred. Through retirement attrition and layoffs by the time I left voluntarily there was only a little over five hundred left.
All of the ‘fat’ was gone and if someone took vacation or got sick then someone had to be offered overtime to cover the necessary shifts. The union guys loved that, the Exempt personnel were burned out with fifty or sixty hour weeks and only being compensated for forty hours.
So yeah, in my experience being offered all of the time off you needed was/is seen as a ploy to discover who could be laid off next.
Sounds like your company didn't need a system for determining who needed to be laid off next other than raw numbers. We have 500, we want to go to 450, grab 50 and let them go. In a place like that it's far more likely that the ones making the higher salary would be first on the chopping block.