It appears that the avast team want
positive feedback that their
free (as in you pay nothing for it) product continues to be used. This seems to me a remarkably trivial request of all of us freeloaders - that we confirm we are still using the product.
Auto-renewal completely overrides the ability of the avast team to know that we want to keep on getting this free service.
If you don't like
free ... by all means pay to get reminders until the crack of doom.
What's the hardship in cooperating to get free stuff?