Will "tips and notes" disappear completely?
They were not avaibale in mobile application, and now they disappeared from mobile version of site.
Are they considered an evil by developers?
No, Luis actually said in an AMA this year that they want to add tips and notes to the apps. I doubt they will ever disappear from the desktop website.
I've seen something like that in some new lessons appeared in update this month. But what currently exists - now completely unavailable from mobile.