Just for clarification: it was only the assignments that were due on the day that they were absent that are due on the day they come back. The rest have as many days as you missed.
This is so students don’t miss a day and then get another 2 days to make up an assignment.
Yes, if you’re in the urgent care 10 minutes after you get out of school and very ill the whole time you are out, teachers will probably be flexible. However, that doesn’t seem to be the case here.