Just look at Google's hostility towards maintaining standardized IMAP/SMTP support for third party mail clients. Google Apps and Office 365 would drop IMAP access to their services in a heartbeat if they could.
Furthermore a lot of our online interactions are moving from open formats like Usenet, IRC, XMPP and SMTP/IMAP to closed off walled gardens like Twitter, Instagram and Facebook.
This artist's online presence could have been entirely based on Instagram and Twitter for example and I bet many (younger than I) folks nowadays do eschew email for other forms of communication.
I don't think self sufficiency in communication is a problem the end user can be realistically expected to solve. It's up to engineers and technology stake holders to try and push us back to a more open way of using these apps and provide standards based communication.
I don't know how the heck we'll do that - I don't see any user pressure for companies to even try, but news like this troubles me and I think it's going to get much worse before people realize their data isn't their own and push for it to get better.