[whpalmer4]

I am skeptical that the groups will spontaneously open without user action. They may appear to do so if they were open when they last contained something and something is moved in, as you mention.

In any case, your only current option to remove them is to use the Due Soon setting in the view bar which will restrict the view to show at most a relative handful of days into the future, whatever you have set for the Due Soon interval in the preferences. Admittedly, this doesn't work so well if you want to look beyond the due soon horizon. Or take the easy approach and adjust the scroll bar position until the offending items/groups are out of sight.

As always, Help->Send Feedback to make a feature request...