I wrote a post in April last year when we were observing some projects that would not update their keynote schedules during printing.
When they issued 2018.3 that issue was reportedly resolved. Moving forward into 2019 and 2020 versions it seems true. However we've seen a few projects that seem to continue to exhibit the problem. Specifically a keynote schedule does not show all of the keynotes that are actually visible in views on the sheet.
With these troubled project files we can force a regeneration IF each sheet view is open during printing. Like before turning the annotation crop boundary off/on or on/off will cause a regeneration too. However printing is when it matters the most. More testing is required before I can be certain there is an ongoing issue in the more recent releases but these projects do exhibit the problem in more recent versions too.
The current solution is to open all the sheets that must print first and then print to PDF. Alternately open a sheet view and print and repeat for all required sheets. If all the views are open then the revision schedule regenerates (you can watch it happen). The sheet view does not have to have Revit's focus, just has to be open in the background at least. Any sheet views that are not open won't refresh.