When need is deactivated, should not be visible to waitlisted users

Hi! In April we had to deactivate all of our May Daytime Food Packing and May Evening Food Packing custom shifts. 

We emailed everyone who was registered and then we deactivated the opportunity. But the May shifts are still showing up for users who added themselves to the waitlist. Below is the view of one of our volunteers, Carl E. -- the bottom three shifts are from a deactivated opportunity.

This is a problem because sometimes our waitlisted people just show up anyway.

I also think it is a bug, because for April Evening Food Packing, instead of deactivating the opportunity, we removed some of the shifts, for example, we removed shifts on April 28 and 29 and I cannot find any of our regular volunteers who have those shifts on their waitlist Volunteer Opportunities. 

So I believe that removing a shift also removes the waitlist response where as deactivating an opportunity does not remove the waitlist response. Both actions should remove the waitlist response, to avoid confusion! Thanks!