Strange. Maybe the leave starts at the end of the week?

I think this is a question you have to ask your SM.

They are probably still on LOA at the time of the schedule being created but are scheduled to be released to work that week.

If it’s a paid LOA, they’re still given the minimum hours to maintain benefits, so they’ll appear on the schedule for that number of hours to be scheduled and paid out for them, though they won’t show up to work them, if that makes sense

Those are either hours they are still being compensated even tho they aren't working, open shifts to take while they're not there, or what happens most often, that person might have quit and now those shifts have literally no one.