Hacker News Reader

Whatsapp blocked telegram.me links at some point (I think when it was acquired by facebook, inciting an other mass exodus)

How? WhatsApp messages are e2ee. Via the preview pings maybe?

If I remember, telegram.me links would not be identified as URLs requiring manual copy-paste. They didn't have link previews back then.

The messages are E2EE only in transit. They can always tweak clients for things like this.