YES — for the WhatsApp Flare to work. This is a security feature, not a limitation. Here's why:
If you're not WhatsApp contacts: You can add each other (takes 30 seconds), use manual entry mode, scan QR code in person, or share the link via another messaging app.
Requiring WhatsApp contacts creates a trusted channel for the handshake. Here's what it prevents:
It's the same reason WhatsApp doesn't let strangers message you without an invite.
You have several options:
The Flare is designed for the most common scenario: two people who already communicate via WhatsApp and want a more private channel for their actual conversation.