There's nothing secret about it. CS has been in the news openly talking about how layoffs are part of his transformation effort. Layoffs are every Tuesday that follows a payday. This is due to timing within the 60-day notice period so your final paycheck is for a full two week time period.
They published about 13,000 headcount reduction last year in the public investor reports filed with the SEC and Charlie has said they will need to cut deeper this year. It is implied they are only doing something like 24 layoffs out of 26 opportunities (26 pay periods) so if the 2024 target is 15,000 layoffs, that's about 625 layoffs per cycle.
Another person posted that the company has the capacity to do up to 1000 layoffs per cycle but that it's hard on the layoff department to process that many. 600 is a more realistic number per cycle.
An on point post by @rnv+1rqHIKNt.