Does this need a notification?
 

I reserved a flight from Denver to New Delhi by Lufthansa. The flight was supposed to leave at 5:35 and the new time is 5:45. There is over 2 hr stopover at Frankfurt.
Does a 10 min late start need a notification? The email doesn't state that was the change-it mentions cancelling, rescheduling, alternative flight.....etc
I can understand notification if a long delay that would affect transfer at FRG.
How much delay that you think would be appropriate top notify if there is no stop over or there is over two hour connection time!

To keep things simple, any change should have a notification. If not, you can be sure someone would be here complaining.

I got a similar notification for a 4 minute schedule change. Given that such changes are quite common in the airline industry, some basic rules would be prudent.

You should probably sue them.

If it just left ten minutes late on the day you probably wouldn't notice and certainly wouldn't give it a second thought.

This is in the same category as a dented can or a torn teabag. You should demand, as a minimum, compensation in seven figures (their choice of USD, Euros, GBP or SFR) and free first-class flights for life.

Well, you could think of it this way. Let's say you got an 8 min delay notification, followed by a 10 min delay notification, followed by another 8 min delay notification. If they didn't send any emails, you might not realize you were staring at a nearly 30 minute delay.