There may not be a formal “advance notice” but in CSBB people get their relocation offer first. They have 30 days to accept or deny it and if they decline it, then it’s usually a couple of months before they get the actual layoff notice. Again, for CSBB, most people have to work the 60 day notice.
For example, wave 2 got relo offer in June, layoff notice in September, last day in November.
OP- if all of the above applies to you… on your last day of work you’ll get an off cycle paycheck that includes your PTO balance. Mine didn’t appear in workday or my account until about mid day on my last day of work.
Then you skip the next scheduled pay period (since you were paid on your last day) and then your severance payments kick in.