If your teacher is absent, he (me) take the time and trouble to send a notice no matter what the time is for 3 reasons:
1. I respect people and especially my students
2. I care about you all so you dont waste your time coming all the way here for nothing.
3. I was well educated.
I would appreciate a notice if a whole group except 2 students is absent. No matter what the reason is. You should have sent me a notice.
No need to write anything now.
Thanks for reading.