“Even if this article is accurate, it doesn’t really mean much” millions of users (to start) moving away from a platform does matter; it matters for those users and could evolve into a larger movement in time.

“Let’s assume they fully moved and stopped using WhatsApp (very unlikely)” why is this “very unlikely”, I’ve uninstalled WhatsApp, I will never install WhatsApp again, ever. I guess I’m part of the “very unlikely” group.