It will reload all the saved states of each pattern.
So as an example lets say you have a set of four patterns.
You load the project and your jamming away changing filter setting and steps etc.
You like the changes to pattern 4 so you save that pattern with FUNC+YES (quick temp save)
Now you want to save the project again but you dont want to save all the setting changes on patterns 1-3, but you want to keep the updated pattern 4.
So you use the ‘Reload temp states all patterns’ , and this reloads the temp states of all the patterns in the project, and because you FUNC+YES temp saved pattern 4, it keeps all the edits from this jam session. Patterns 1-3 load the temp states from when you loaded the project.
Then you save, confident you havent ruined any settings on the patterns that you didn’t update.
Currently save project resaves every pattern