Any kind of sharing via evernote's internal systems means making the email address of my coworker available for evernote. As note collaboration still is an essential part of the program, I sincerely doubt that GDPR has anything to do with the decision to drop share by email. To the contrary, Evernote has slowly and steadlily worked towards user lock-in, preferring to force also those who receive notes to become evernote users. I find this quite rude, and so does my coworkers. So for me, after 12+ years as a faithful customer, I have started to look for alternative solutions.