A lot of people want to get off Facebook but one reason why they stick around is Facebook Events. A lot of clubs and artists use Facebook Events to post about upcoming shows and it is a great way to be alerted about stuff happening in your town. I wonder if that functionality could be replicated, you would probably need to "follow" someone on there too and I understand Proton is not a social network so I'm not sure how it would work but if Proton managed to come up with something, it would be great!