Of all the changes I've seen made on Medium in my over two years here, this is the one that bothers me the very most. I think it saps the platform's authentic discoverability in many ways. I actually wrote a piece in similar vain when I learned of this change myself if you're at all curious: https://medium.com/thought-thinkers/the-end-to-free-non-member-reads-on-medium-da4b8d63c1fe
Like you, I'd had a few pieces achieve success mostly through google searches and was really frustrated to learn that each person who opened it in that way would be unable to read the piece. What I've begun doing lately is, as soon as a piece is published, attaching a friend link to the very top of it in for anyone who might discover the article externally or not be a member.
Thanks for sending this one in, Victoria!